Data and instructions are given to the computer to perform a specific task that is called Input. You know data consists of raw facts & figures just like a b c or 1234. This is the unprocessed form of data because it does not specify something clearly. This data is given to the computer by using particular devices named computer input devices. In this way we get results by the PC output devices. So that we can say in simple term,
“A computer input device is a hardware component that is used to enter data and instruction into the computer to perform specific task”.
Following are few of the important input devices which are used in a computer:
- Digital Camera
- Light Pen
- Touch Screen
Now we describe one by one briefly.
The keyboard is an input device that is used most widely to enter data. It has very similar to the conventional typewriter with about 101 keys. The arrangement of keys on the keyboard is known the layout. The most popular layout is QWERTY but Dvorak layout is also used. The keys on a computer keyboard are classified as follow:
- Numeric Keypad: It consists of arithmetic operation (+ – * /) and number keys (0 to 9) to perform arithmetic like addition, subtraction, multiplying These are located on the right side of a conventional keyboard.
- Alphanumeric Keys: Include alphabets (A to Z) and numbers (0 to 9).
- Functions Keys: Function keys perform particular kind of functions. Keys are (F1 to F12).
- Arrows keys: Control the cursor around the screen.
- Alt & Ctrl: Pressed to gather with other keys to give commands.
- Escape & Shift: Escape is used to cancel an operation & Shift key allows entering punctuation marks or capital letters.
It is one of the most popular pointing devices which are being used frequently to control cursor around the screen. It has two-to -three buttons that are used to select an object or opening a program. It is available in following types.
It contains left, right buttons, and middle scrolling button as well that is used to page up/down means scrolling. The main thing is that it has a ball under it that rotates when a user has been dragging over there. In this way screen pointer is controlled.
It is very similar to the wheel mouse but the difference is that it emits a laser beam of light to get through mouse pad instead of rolling ball, remaining other functions are same like wheel mouse.
Such type of mouse does not require a cable to attach. It consists with internal battery like dry cell, so that it performs all other mouse functions using wireless technology.
It is also a pointing device. We move it on the screen just like an ordinary pen but it works with electricity. It is used for drawing maps, pictures & also has no alphabetic keys. Simply it sends input to the computer when a user touches on the screen. That is why graphic designers & Engineers use it most of the time.
It is another computer input device having “Base” & “Stick” is known joystick. The stick is connected to the base, so the stick can move freely up to the 180 Degree that is used to move an object on the screen by moving it. It provides beautiful functions & facilities to control video games around the screen. Therefore this one is very popular device among children.
The trackball is very similar to the mouse but it has two click buttons & a ball that can circulate freely. So a user controls the mouse pointer on the screen by moving the ball & performs click functions by pressing buttons just like a mouse. But the advantage of the trackball is that take very less space to move so we can use it while traveling in Bus, Plans. In simple words, it is an alternative to the mouse.
It converts hard copy into soft copy. It scans any of written or image things and then converts into digital form. So a user can use the scanned document for printing, uploading or to send via mail. Now a day latest scanners provide a facility of OCR stands for Optical Character Recognition. In fact, OCR is software that converts the document image into text format. So a user can edit it in Word Processor like MS Word.
Digital camera is a very popular input device that is used to capture photos. These pictures can be transferred to the computer as it can be connected to a computer through USB very easily. Many cameras provide facility to edit pictures with the help of built-in functions. Pictures taken by the camera are stored in its own memory. So no need it to record them on extra film.
It is a Computer Video Camera that is used for video chatting, Video Calls, sending E-mails to friends with full motion attachments etc. In personal computers, a webcam is attached via USB but so many laptops & Mobiles have a built-in webcam.
The touch screen is very reliable in these days; this input device is used in mobile phones and tablets. Now computer screens are also being changed by inserting touch system because it is very easy to use than key pressing.
BCR stands for Bar Code Reader, it is an input device. Different kinds of products have lines of different thickness in a particular place. So this code represents the data, and the device contains the photocell that read the Bar Code to show actual data. Shopkeepers use it to know the price & information of an item.
Electronic Card Reader:
It is also an input device that is used by bank account holders; it is also known magnetic stripe reader. It reads all information when someone swaps ATM or VISA card on it. Usage of ATM card is increasing rapidly day by day in all over the world.
At the end, we get results that all instruments that are used to given instructions to the computer are called computer input devices. As like characters are typed by the keyboard, voice is entered by microphone same pictures are captured by digital camera and so on.
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