What is Plotter

A plotter is an output device that is used to produce image- quality graphics in a variety of colors. Plotters are used to create maps,architectural drawings, graphs and charts. A plotter works by drawing lines on paper using pens held in a mechanical arm.

Types Of Plotters:

Different types of plotters are as follows:

1.  Flatbed Plotter
2.  Drum Plotter

 1. Flatbed Plotter:

Flatbed plotter is used to plot or draw images. It contains pen for drawing images. The paper is placed on table-like surface. Software instructs the pen to move down on the paper.The pen then moves on the paper for creating images. Most flatbed plotters have one or more pens of different colors and widths.    

2. Drum Plotter:

 Drum plotter uses a rotating drum or cylinder. The drawing pens are mounted on the drum. The pens move to the left and right as the drum rotates. This movement creates the desired image. The advantage of drum plotter is that the length of the plot is almost unlimited. The roll paper can be used to draw very lengthy images. The width of the image depends on the width of the drum.

Printers

A printer is an out put device that prints characters, symbols and graphics on paper. The printed output is called hard copy. Print resolution is commonly measured in dots per inch(dpi). Different categories of printers are as follows:

• 1. Impact Printers:

An impact printer works like a typewriter. It prints characters or images by striking a print hammer or set of pins against an inked ribbon. The ink is pressed from the ribbon on the paper to produce the output. Impact printers are the oldest print technologies which are still produced. The impact printers are used where low-cost printing is required. Three most common forms of impact printers are  

1.dot matrix printers,

2.daisy wheel printer 

3. line printer.

2. Non Impact Printers:

A non impact printer prints characters and graphics on paper without striking paper. The characters are printed on paper with different means such as laser. Some printers use spray ink while others use heat and pressure to create images. These printers are faster than impact printers. However, they are more costly than impact printers. The produce no noise during printing. The print quality of non-impact printers is better than impact printers.

Different kinds of non-impact printers are as follows:

• Laser Printer

• Inkjet Printer

•  Thermal Printer

• Laser Printer:

LASER stands for Light Amplification by Stimulated Emission of Radiation. The laser printer is a non-impact printer. Its working is similar to photocopying machine. It uses laser beams to burn special powder on the page to create a permanent image. The powder is contained in the toner. Laser printer prints complete page at a time. It is also known as page printer. The printing speed of laser printers for home and small office user is 12 to 45 pages per minute (ppm). The printing speed of laser printer for large business user is 150 ppm or more. The speed depends on the contents being printed. The plain text i printed faster than graphics. Laser printer prints text ad graphics in high quality resolution. A typical laser printer provides a resolution of 1200 DPI or more. It also prints at higher speed than inkjet and dot matrix printers. It does not make much noise. Laser printer is mostly used in the business field. The black and white printing cost of laser printer is less than inkjet printers. Laser printers are available in black and white as well as color models.

•  Inkjet Printer:

An ink-jet printer is a type of non-impact printer. It prints characters and graphics by spraying tiny drops of liquid ink on paper. These printers can produce quality text and graphics in both-and-white and color including photos. A typical inkjet printer provides a resolution of 600 DPI or more. The price of inkjet printers is less than laser printers. However, they are slower than laser printers. Most inkjet printers can print from 10 to 35 pages per minute. However, they print graphics and color at slower rate. The print quality of inkjet printers is higher than dot matrix printer. They are also comparatively inexpensive.Most inkjet printers usually have two print cartridges. One cartridge contains black ink and the other contains color.

• Thermal Printer: 

Thermal printer is a printer that uses heat process to transfer colored dyes or inks to the paper. Thermal printer is the best color printers currently available but it is also very expensive. It was originally used only in scientific labs to record data. This printer is used to produce very high-quality color artwork and text. Professional applications requiring very high image quality such as photo studio, medical labs and security identification systems use thermal printers.The cost of this printer is thousands of dollars and it prints images in a wide range or sizes.

4. Photo Printer:

Photo printer is a color printer that is specially designed to print high-quality photographs. It is also called snapshot printer. Some photo printers print photos of one or two sizes only. Many photo printers have a built- in card slot. The printer can print digital photos directly from a media card. It means that there is no need to transfer the images from media card to the computer to print them. Some photo printers also have build-in LCD color screens. The user can view pictures before printing them. Some photo printers also have built-in LCD color screens. The user can view pictures before printing them.
5. Portable Printer:

Portable printer is a small, light - weight and battery- powered printer. It can be used by mobile users to print images from a notebook computer, Table PC or PDA while traveling. Its size is a bit wider than the page on which it prints. Portable printer fits in briefcase easily. Many printers connect to parallel port or USB port. Some portable printers have built in wireless port to communicate with computer wirelessly.
 6. Label and postage Printer:

Label printer is a small printer. It prints on an adhesive type material that can be placed on different items like envelopes, packages, CDs, toys etc. Many label printers also print bar codes. Postage printer is a special type of label printer. It has a built-in digital scale. It prints postage stamps. It allows the users to buy and print digital postage from their personal computers. The digital postage is also called Internet postage.

Computer Crime

It often involves stealing, using or selling company's personal data. A type of crime that refers to an illegal act involving the Internet is called cyber crime.

• Computer Criminals:

The persons who commit computer crimes are known as computer criminals or cyber criminals. Different types of computer criminals are as follows:
 1.Hacker:

A person who accesses a computer or network illegally is known as hacker. This term was originally used for computer enthusiasts.

2.Cracker:

Cracker is a person who accesses a computer or network illegally for some negative purpose. A cracker may destroy data and steal important information etc.

3. Script Kiddie:

A person who attempts to access a computer or network illegally without technical knowledge is known as script kiddie. The script kiddies often use hacking or cracking software to access computers.

 4.Corporate Spy:
A person who is hired to break into a specific computer is known as corporate spy. Corporate spies have excellent computer and network corporate spy. Corporate spies have excellent computer and network skills. Some organizations hire them to identify security risks in the organization etc.
5. Unethical Employee:
 The unethical employees may access the computer for different reasons. Some may get financial gains by selling confidential information. Some unhappy employee may do this to get revenge etc. 
6. Cyber Extortionist :
A person who uses email as tool for extortion is known as cyber extortionist. Such persons send email to a company with a threat. They tell company to pay money otherwise they will expose confidential information of company etc,
7. Cyber Terrorist:
A person who uses computer Internet or network to destroy or damage computers for political reason is known as cyber terrorist. For example, cyber terrorists may destroy air traffic control system, electricity-generating systems or telecommunication system of a country etc.
Methods Used by Computer Criminals:
 The following methods are used by computer criminals:

• Bomb:

 It is a program that triggers under certain conditions. It is usually activated at a certain date. It may be planted in commercial software like shareware software.

• Data Diddling:

It is a process of changing data before or as it enters the system. The auditors must verify the accuracy of the source data and the processing that accurs.

• Denial of Service:

It slows down a computer system or network. It floods a computer or network with requests for information or data. The server under attack receives so many requests that it cannot respond to legitimate users. 

• Piggybacking:

 It is a process of entering the system by riding on the back of an authorized user. It occurs when an authorized user does not log off the system properly. An illegal user may continue where original user left.

• Salami Technique:

It is a process of getting a small amount of money illegally from a large financial system

• Scavenging :

 It is a process of searching company's trash cans to find useful information. The thieves search garbage and recycling bins of individuals to find bank account numbers and credit card numbers etc.

• Trap Door :

 It is an illegitimate program that is left within a completed legitimate program. It allows subsequent entry by unauthorized user to change the program .

• Trojan Horse:

 It is a program that hides itself within a useful program. It executes illegal, destructive instructions in the middle of the program such as computer game. FormatC is an example of a Trojan Horse.

• Zapping:

 The zapping software is designed to bypass all security systems.

Organizational behavior.

Organizational Behavior is the study of individuals and their behavior within the context of the organization in a workplace setting. It is an interdisciplinary field that includes sociology, psychology,communication and management. Organizational behavior is the study of how organizations can be structures more effectively, and how several events in their outside situations effect organizations. Learning about organizational behavior in today's business environment could help managers build up a better work related understanding of themselves and their subsidiary. With the knowledge managers can achieve a successful career. Since a manager needs to get his job done by the others, to have an organizational behavior skills become a valuable talent.

As the environment of business is always changing, the role of the managers has become more sensitive. In order to know how to handle a new workforce, and deal with the complication of the new environment, the supervisions need to develop their information about attitude and behavior of individuals, and groups in organization. Now we know not only the hard skills are important for get the job done, soft skills are helps managers to do their job more effectively and efficiently. What are hard and soft skills ? Hard skills include written communication, computer problem solving experiences, computer skills, and ability to understand new technologies, international business Organizational behavior has a big area to study. These are many different elements that they are related to each other like a chain. The three important aspects that (a) motivation (b) communication(c) leadership. 

Organizational studies encompass the study of organizations from multiple viewpoints, methods, and levels of analysis. For instance, one textbook divides these multiple viewpoints into three perspectives: modern, symbolic, and postmodern. Another traditional distinction, present especially in American academia, is between the study of '' micro'' organizational behavior which refers to individual and group dynamics in an organizational setting and '' macro'' strategic management and organizational theory which studies whole organizations and industries, how they adapt, and the strategies, structures and contingencies that guide them. To this distinction some scholars have added an interest in '' meso'' scale structures power culture, and the networks of individuals and ie ronit units in organizations and field level analysis which study how whole populations of organizations whenever people interact in organizations, many factors come into play. Modern organizational studies attempt to understand and model these factors. Like all modernist social sciences, organizational studies seek to control, predict, and explain. These is some controversy over the ethics of controlling workers' behavior, as well as the manner in which workers are treated . Organizational behavior is becoming more important in the global economy as people with diverse backgrounds and cultural values must work together effectively and efficiently. It is also under increasing criticism as a field for its ethnocentric and pro-capitalist assumptions.
During the last 20 years, organizational behavior study and practice has developed and expanded through creating integrations with other domains:

• Anthropology became an interesting prism to understanding firms as communities, by introducing concepts like Organizational culture, 'organizational  rituals' and ' symbolic acts' enabling new ways to understand organizations as communities.
• Leadership Understanding , the crucial rile of leadership at various level of an organization in the process of change management. 
• Ethics and their importance as pillars of any vision and one of the most important driving forces in an organization.

Scanners

Scanner reads data or information from a source. This source could be a written document, a price tag, a graphic image or a photograph. A scanning device reads the data or information and then converts it into a form that can be processed by the system unit. Two types of scanning devices are optical scanner and optical readers.

• Optical Scanner

An optical scanner is also known as scanner. It is light-sending input device. It reads printed text and graphics and translates it in digital form. The scanned image can be used for different purposes as follows:

• It can be displayed on screen.

•  It can be printed on the paper.

• It can also be sent via email. 

• It can be posted on a web page.

• It can also be stored permanently for later use.

The typical image scanner scans at a resoultion of 300 or 600 dpi. Resolution describes the sharpness of an image. The quality of scanned image also depends on the resoultion. The scanned image will be brighter and sharper if the scanner provides high resolution. Professional scanners usually scan at 1200 dpi or higher. A higher number of dots generates better quality but also creates a larger file size. Many scanners also provide optical character recognition (OCR) software. OCR software can read the document image and then convert it into text that can be edited in word processor.

• Types of Optical Scanner:

Different types of optical scanners are as follows:

1. Flatbed Scanner:

A flatbed scanner is also called image scanner. It inputs one page at a time. It works like a photocopy machine. The image to be scanned is placed on a glass surface and the scanner records the image. It is generally used at home and office.
2. Sheet-fed Scanner:

A sheet-fed scanner works similarly to a flatbed scanner but documents are inserted on the top of the scanner like a fax machine. This design reduces the scanner's cost and the amount of required space. It also enables automatic sheet feeding. However, this feature also prevents the device from scanning bound-book pages or other documents thicker or larger than a sheet of paper.

3. Handheld Scanner:

A handheld scanner is a portable scanner. It is also called half- page scanners because it can scan only 2 to 5 inches at a time. Handheld scanners are useful to input small amount of data. The scanner must be moved over the image to be scanned by hand. Some handheld scanners include trays to keep the scanner moving in a straight line. It is designed to scan short articles and single lines of data like web addresses, names or phone numbers.

Types of Digital Cameras

• Image Capturing Devices:

The image capturing devices are used to capture original images. Some important image capturing devices are as follows:

• Digital Camera:

Digital camera is an input device. It stores images digitally in its memory rather than recording on film. The pictures taken with a digital camera can be transferred to the computer system. Many digital cameras allow the user to edit the images. The number of digital photos depends on the amount of memory in the camera.The main advantage of digital cameras is that making photos is inexpensive and fast. It does not require any film processing. Most digital cameras store images in internal flash memory. They can also store additional images on mobile storage media like flash memory cards, memory sticks and mini disks etc. Digital cameras can be connected to a computer easily through USB port.

The quality of a digital camera depends on its resolution. Resolution describes the sharpness of an image. Image resolution for digital camera is measured in megapixels. Megapixels are the millions of pixels in a graphic. The digital cameras of eight or more megapixel are now available and produce excellent photos.

• Types Of  Digital Cameras:

Some important digital cameras are as follows:

1. Studio Camera:
2. Field Camera:
3. Point-and-shoot Camera:

No1. Studio Camera:

It is the most expensive digital camera. It is a stationary camera used for professional studio work. It is normally used by professional photographers and journalists.

No 2. Field Camera:

It is a portable camera. It has many lenses and other attachments. It is also very expensive.

No 3. Point and shoot Camera:

It is less expensive and lightweight camera. It provides good quality images for home and small business users.

 Point-and shoot camera provides flash, zoom, automatic focus and special effects. Some cameras also allow to record short video clips. They also provide build in TV out port to display photographs and video clips on TV.

Stress Management

Some organizations provide training to employees on stress management and Employee Assistance Program (EAP). Nearly half of the companies in USA are providing training to employees on ways to handle stress. These programs teach employees the causes and consequences of stress, the way to handle them and some relaxation exercises. These programs are able to alleviate some symptoms of stress, like sleep disturbances and anxiety.Some companies also provide counseling sessions to some employees who also have some personal problems.However, these benefits are short lived in nature as they do not strike the problem at the root, if the genesis of the problem lies somewhere in the work practices being followed by the organization.

• Stress management:

Employers should provide a stress-free work environment, recognize where stress is becoming a problem for staff, and take action to reduce stress.Stress in the workplace reduces productivity, increases management pressures, and makes people ill in many ways, evidence of which is still increasing. Workplace stress affects the performance of the brain, including functions of work performance: memory, concentration, and learning. In UK over 13 million working days are lost every year because of stress. Stress is believed to trigger 70% of visits to doctors, and 85% of serious illnesses. Stress at work also provides a serious risk of litigation for all employers and organizations, carrying significant liabilities for damages, bad  publicity and loss of reputation. Dealing with stress-related claims also consumes vast amounts of management time. So, there are clearly strong economic and financial reasons for organizations to manage and reduce stress at work, aside from the obvious humanitarian and ethical considerations. If you are suffering from stress yourself the stress management   guidelines here are just as relevant. See the workplace stress research crucifies below. Stress and stress management are directly related to personal Well-being and specifically to workplace well-being. See the separate article on workplace well being for a detailed explanation of well-being and its relevance to modern work and management.

• Quick stress reduction techniques:

If you are stressed, do one or all of these things, in whatever order that takes your fancy. These ideas can also be adapted for team development exercises. The key to  De-stressing in the moment is getting away from or removing you from the stress-or. Developing new habits which regularly remove you and distract you from stressors and stressful situations and pressures is essentially how to manage stress on a more permanent basis. In this modern world it is difficult if not impossible to change stressful situations. What we can do however is change and reduce our exposure to those stressful situations. These stress reduction ideas and techniques are based on that simple principle.These tips won't change the situation causing the stress, but they will, more importantly, enable you to change your reaction and relationship to the stressful situations. And in keeping with the tone of this stress tips section, and since color is regarded by many as a factor in affecting mood, the calming shade of green is used for the headings...

• Stress Causes:

Stress is caused by various factors- not all of which are work- related of course, (which incidentally doesn't reduce the employer's obligation to protect against the causes of stress at work). Causes of stress - known as stressors- are in two categories: external stressors and internal stressors.

• External Stressors:

Physical conditions such as heat or cold, stressful psychological environments such as working conditions and abusive relationship, eg, bullying.

• Internal Stressors:

Physical ailments such as infection or inflammation, or psychological problems such as worrying about something. From the above,it is easy to see that work can be a source of both external and internal stressors. Stressors are also described as either short-term (acute)or long- term (chronic):

• Stress effects on health and performance: 

Stress is proven beyond doubt to make people ill, and evidence is increasing as to number of ailments and diseases caused by stress. Stress is now known to contribute to heart disease, it causes hypertension and high blood pressure, and impairs the immune system. Stress is also linked to strokes, IBS ( irritable bowel syndrome), ulcers, diabetes, muscle and joint pain miscarriage during pregnancy, allergies, alopecia and even premature tooth loss.

• Signs Of Stress:

• Sleep difficulties
• loss of appetite 
• Poor concentration or poor memory retention
• Performance dip
• uncharacteristic errors or missed deadlines 
• anger or tantrums
• violent or anti-social behavior
• emotional outbursts
• alcohol or drug abuse
• nervous habits

Methods of Personal stress management and stress relief
If  you are suffering from work related stress and it's beginning to affect, or already affecting your health,  Stop to think:  why are you taking this risk with your body and mind ? Lives short enough as it is: illness is all around us: why make matters worse? Commit to change before one day change is forced upon you. If you recognize signs of stress in a staff member, especially if you are that person's manager, don't  ignore it do something about it. It is your duty to do so. If you do not feel capable of dealing with the situation, do not ignore it; you must refer it to someone who can deal with it. You must also look for signs of non-work related stressors or factors that increase susceptibility to stress, because these will make a person more vulnerable to work-related stressors. Successful stress management frequently relies on reducing stress susceptibility and removing the stresssors, and often factors will be both contributing to susceptibility and a direct cause. 

Types Of Mouse

What is Mouse:

Mouse is a popular pointing device. It is used to input instructions with a pointer on the screen.Mouse is moved on a flat surface to control the movement of the cursor or pointer on the screen. A mouse usually has two or three buttons. These buttons are used to perform different tasks such as selecting an object or opening a program etc.It may also include a wheel to scroll through long documents.

Types Of Mouse:

Different types of mouse are as follows:

1.Mechanical Mouse:

Mechanical mouse contains a rubber or metal ball inside it .The movement of the cursor depends on the movement of the ball. This mouse is normally used on mouse pad. Mouse pad is a small pad of rubber or foam to provide easy movement of  the mouse. It protects the mouse from dust and dirt.
 2. Optical Mouse:

Optical mouse contains no ball inside it. It uses a device that emits light to detect the mouse movement. Optical sensor or laser is used in these types of mouse. It is more expensive than mechanical mouse. Optical mouse is becoming popular now a days.

3. Wireless / Cordless Mouse:

 Wireless or cordless mouse is a type of mouse that does not require a wire to work. It transmits data using wireless technology like radio waves or infrared light waves.
 4. Air Mouse:

Air mouse is a motion-sensing mouse. It can be used to control objects, media players and slide shows by moving the mouse in specific directions through the air.For example, the user can raise the mouse up to increase the volume of media player. The air mouse works in the air by detecting hand motion. It does not to work on the surface.

Presentation Software

Presentation software is a type of application software that uses graphics,animation,sound and data or information to make visual presentation. These presentations can be used directly on the computer screen. The presentations can also be viewed as slides on a large monitor or projection screen. The user can also print them for different uses.Some examples of presentation software are MS PowerPoint, Keynote and presentations.

Features Of Presentation Software

• Formatting: Presentation software has a wide range of formatting facilities. You can change the color, background color, size and style of your text. 
• Printing: Presentation software provides printing facility. The user can print slides to get a hard copy.Printing can be of whole presentation or of any range of pages.
• Predefined Formats: Presentation software provides many predefined presentation formats with different background colors, text styles and graphics for the presentation.
• Slide Layout: Presentation software provides different slide layouts. The user can select any layout for your presentation..
• Audio and Video Presentation software provides the facility to add sounds and videos in the presentation. It enhances the effects of the presentation.

• Auto Shapes:  Presentation software allows the user to draw different geometrical shapes, arrows, flowchart symbols, starts and banners on the slides. 
• Clip art gallery: Presentation software includes a clip art  gallery that contains images, photos, video clips and audio clips for the presentations. 
• Spelling and Grammar: Spelling and Grammar features is used to detect and correct the spelling and grammatical mistakes in the presentation.
• Animation: Presentation software provides the facility to animate the contents of presentations. Different types of movements can be applied to different components of the presentation. It makes the presentation more attractive. 
• Slide Transition: Presentation software can be used to apply special effects to the transition between slides. Slide transitions are the visual movements as one slide changes to another. By default, one slide simply replaces previous screen.
• Slide Timing: Slide timing is used to set the timing of slides. The presentation automatically displays the next slide after a preset delay. The user can rehearse the presentation to know the time required to complete the presentation.
• Speaker Notes: Presentation software provides the facility to add speaker notes to a presentation. The notes can be used to remember important points during presentation or to give to the audience.

Mobile Devices

Mobile computing devices are portable electronic tools such as cell phones, Pager and MP3 player etc.

People use these devices to communicate with others, remain productive and access a wide range of information from different sources.

1.Paging Device:

A paging device is also called pager. It is a small wireless device that is used to receive and sometimes send numeric and text messages on a small display screen.Pagers are cheep and have very low power consumption.

Different types of pagers are as follows:

• Numeric pager: It displays only numbers on the screen. It tells the user that he has received a page and provides him with the number to call.Numeric pagers do not allow the user to send a response.
• Alphanumeric pager:It can receive numeric and text messages.It does not allow the user to send messages.
• Two-way pagers:It can receive and send messages. It has a built-in keyboard to compose text messages. Advanced two-way pager also includes an address book. It can notify the user of e-mail. It also allows the user to check email and send replies.

2.Cell Phone:

Cell phones provide all of the features available on a traditional telephone.It includes auto-redial, call timers and voice-mail. Some cell phones also feature voice-activated dialing that is important for hands- free operation. It can offer Internet access, text messaging, personal information management (PIM) features, voice recording and digital image and video capture.

• Cell Phone Hardware:

Cell phone has a processor, memory and input and output devices. The processor coordinates sending data between the components inside the phone. It also runs cell phone's OS that provides a user interface to change phone settings, store information etc.Full- featured cell phones use Symbian OS or Windows Mobile operating system. The operating system is stored in ROM. Other phone data is stored in separate internal memory chips. Full- featured phones have 16 MB of memory to store contact data, ringtones, images,  and small software applications such as currency converters or world clock.The input devices of a cell phone are primarily the microphone and a keypad.Some phones use Palm Graffiti pad as well as touch- sensitive screens to input data. Many cell phones include digital cameras. Cell phone output devices include a speaker and an LCD display. Higher-end models include full-color,high-resolution plasma displays.

• Cell phone Features: 

Some cell hone features are as follows:

SMS: SMS stands for Short Message Service. It is a technology to send short text messages up to 160 characters over mobile networks.The numeric keypad is used to send SMS messages from cell phone.

MMS: MMS stands for Multimedia Message Service. It is used to send messages that include text, sound, images and video clips to other phones or e-mail addresses.
Cell phone Internet Connectivity:

• Cell phone connects at a speed of 200 to 300 Kbps.
• It is difficult to display Web Pages on cell phones without a great deal of horizontal scrolling to view content. 
• Micro browser software is optimized to display Web content on a smaller screen.
• A popular feature of cell phones with Internet access is checking e-mail.

3.Portable Media Player:

Portable media player (PMP) is a small portable device such as an i pad to play MP3 files anywhere. MP3 is a format for efficiently storing music as digital files. Digital files use special data formats such as AVI or MPEG-4 and can hold video, audio or images. Inexpensive PMPs use built- in flash memory to store files. Some of the PMPs use flash memory to add storage capacity by purchasing removable flash memory cards.Other PMPs use a hard disk drive and can store a much larger amount of music.Another factor that determines how much music a player can hold is the quality of the MP3 music files. The sampling rate is the number of times per second the music is measured and converted to a digital value. Sampling rates are measured in kilobits per second (Kbps). The higher sampling rate increases the quality but also increases the file size.

4.Pod casting:

Pod casting allows users to download and listen audio content on their MP3 players at any time.Pod casting is paving the way to enable anyone to create a radio show at home and to easily distribute it to an audience.Plugging your i pad into a data port on your computer causes synchronization. The i pad searches i Tunes for new content and automatically transfers it.

Types Of Keyboard

Different types of keyboards are as follows:

1. Qwerty Keyboard
2. Enhanced Keyboard
3. Cordless Keyboard
4. Portable Keyboard
5. Ergonomic Keyboard
6. Gaming Keyboard
7. Virtual Keyboard

1. QWERTY Keyboard:

                                                       

A standard keyboard is normally called QWERTY keyboard. This is because the first six keys on top row of letters on these keyboards are Q,W,E,R,T,Y.

2.Enhanced Keyboard:

An enhanced keyboard contains twelve function keys. It contains two control keys, two ALT keys, arrow keys and additional keys between the typing area and numeric keypad.

 3.Cordless Keyboard:

A keyboard that requires no wire is called cordless keyboard or wireless keyboard. It transmits data using wireless technology like radio wares or infrared light waves.Cordless keyboards are available in a variety of features and styles.Many cordless keyboards must be within the line of sight of the receiver with a maximum range of around 10 feet. A wireless keyboard using radio signals provides a range of to 100 feet.

4. Portable Keyboard:

 A keyboard that can be easily attached or removed from a handheld computer is called portable keyboard.

5.Ergonomic Keyboard:

A keyboard that is specially designed to reduce the chance of wrist injuries during typing is called ergonomic keyboard. The goal of this board is to provide comfort, efficiency and safety. The users who spend a lot of time in typing may experience repetitive strain injuries of wrist and hands. This keyboard is manufactured to avoid these injuries.
6.Gaming Keyboard:

A gaming keyboard is a type of keyboard that is specially designed for playing games on the computer. It includes programmable keys to customize the keyboard for the game being played. The keys on gaming keyboards light up to be visible in all lighting conditions.

7.Virtual Keyboard:
A virtual keyboard is a special type of keyboard. The user types on optical- detectable surface or within a wireless area rather than pressing physical keys. This system provides the capability of full keyboard to the users of small handheld device such as cellular telephone or a personal digital assistant.Different technologies are used in virtual keyboards. In one technology, the keyboard is projected optically on flat surface. The user touches the image of a key. The optical device detects the stroke and sends it to the computer. In another technology, keyboard is projected on an area. The selected keys are transmitted as wireless signals using Bluetooth technology.A virtual keyboard is also called Projection Keyboard. VKEY is the trademark name of the virtual keyboard developed by Virtual Devices Inc.

Keyboard

Keyboard:

Keyboard is the most commonly used input device. Data is mostly entered using a keyboard. The buttons on the keyboard are called keys. A keyboard contains over 100 keys. The arrangement of keys on keyboard is called its layout. The most popular keyboard layouts are QWERTY and Dvorak.The keys on computer keyboards are often classified as follows: 

•  Numeric Keypad:

Numeric keypad is located on the right hand side of most keyboards. It has arithmetic operators keys 

 +, - ,* , / that  are used in arithmetic operations and digits from 0 to 9 . It also has a key Num Lock. When this key is off, the keypad cannot be used to type numbers. 

• Function Keys:

Function keys from F1 to F12 perform special functions. Their function depends on the software being used in the computer.

• Alphanumeric keys  

Alphanumeric keys include all letter keys in alphabet (A to Z) and digits from 0 to 9. 

• Backspace Key:

Backspace key is used to delete single character on the left of the cursor on the screen. 

• Enter Key:

Enter key is used to enter command or input data in the computer. 

• Caps Lock Key:

Caps Lock is a toggle key. The characters appear in uppercase if it is pressed. The characters appear in lowercase if it is not pressed. Numbers and symbols are not affected. The status light under''Caps Lock'' turns on when it is pressed.

• Tab Key:

Tab Key is used to move the cursor to the next tab stop. It is also used in dialog boxes to move from one option or field to another. 

• Modifier Keys:

These are used to modify the input of other keys. A specific key is pressed while holding down one of these keys to achieve required result. These keys are as follows:

1.Control Keys :

CTRL keys produce different results depending on type of software.Sometimes this key is used with other keys as shortcut to some commands. For example CTRL+O is used to open a new file.

2.Alt Keys:

alt keys are always used in combination with other keys to perform special functions. In windows- based programs, these keys are used to navigate menus and dialog boxes without using a mouse.

3.Shift Keys:

It is used to output capital letter or special symbol.In most word processors, it is used with various cursor movement keys to select text for editing.

• Cursor-Movement Keys:

 These keys are used to move around the screen and are as follows:

1.Home: 
Home key is normally used in word processing or text editors to move cursor to the top of screen.

2.End: 
End  key is normally used in word processing to move the cursor to the right of screen or to the end of screen or document.
3.Arrows:
The keys that move the cursor are called Arrow Keys or Cursor Control Keys. These keys have an up arrow , a down arrow , a left arrow, and right arrow. 
4.Page Up:
Pg Up key is normally used in word processing or other applications to move the cursor one page up on screen.
5.PageDown:

PgDn key is normally used in word processing or other applications to move the cursor one page down on screen.

Special-Purpose Keys:

These keys are used for special purposes and are as follows:
Esc:  
ESC key is used to terminate command or current task.
Delete: 
It is used to delete the character to the right side of the cursor. It is also used to delete the selected object.
Insert:
It is a toggle key used to switch between Insert Mode and Overtype Mode. 
Print Screen: 
It is used to capture everything that appears on the screen.
Scroll Lock:It locks and unlocks the cursor on screen in some programs. The cursor moves normally when it is turned off. It does not work in all programs.
Pause / Break:It is used to pause screen when information is too fast to read.