Input and output devices

Computers would be useless if they did not provide interaction with users, they could not receive instructions or deliver the results if their work. Input devices accept data and instructions from the user or from another computer system such as computer on the Internet.Output devices return processed data back to the user or to another computer system.The most common input device is the keyboard, which accepts letters, numbers, and commands from the user. Another popular input device is the Mouse , which less you select options from on-screen menus. You use a mouse by moving it across a flat surface and pressing its buttons. Other popular input devices are trackballs, touch pads, joysticks, scanners, digital cameras and microphones.


The mouse , trackball and touch pad enable you to draw a point or the screen. The joystick is especially well suited for playing fast - moving video games. A scanner can copy a printed page of text or a graphic into the computer's memory, eliminating the time - consuming step of typing input or creating an image from scratch. Digital cameras record live images that can be viewed and edited on the computer. A microphone or CD player attached to the computer enables you to add the sound of a voice or a music selection.

The function of an output device is present processed data to the user. The most common output devices are the display screen, known as the monitor, and the printer. The computer sends output to the monitor when the user needs only to see the output. It sends output to the printer when the user needs a paper copy also called a " hard copy", Just as computers can accept sound as input, they can use stereo speakers or headphones as output devices to produce sound.

Some types of hardware can act as both input and output devices. One example is the Touch screen, a type of monitor that display text or icons you can touch. Touch  screens are popular in museums and libraries, where they help direct people to specific areas. In bookstores and music stores, touch screens enable customers to locate an item quickly  without wandering the aisles or searching through card catalogs. Touch screens are even used in gambling casinos, where they provide a fun and non mechanical interface to slot machines.when you touch the screen, special sensors detect the touch, then the computer calculates the point on the screen where you placed your finger. Depending on the location of the touch, the computer responds by displaying new data.

The most common types of devices that can perform both input and output are communication devices, which connect one computer to another - a process known as networking. among the many kinds of communication devices, the most common are moderns, which enable computers to communicate through telephone lines or cable television systems and network interface cards (NICs), which let users connect a group of computers to share data and devices.

Earn upto Rs.9,000 pm checking Emails. Join now!