CS101 Computer Basic
Hardware components used to send any data or instruction to the computer are called input devices. These components get the data and instructions from the user or any other device and convert it into machine language before sending it to the computer. So let’s know about some input devices –
The keyboard is the most commonly used input device. There are many types of wired and wireless keyboards available in the market. As its name, it consists of many keys or buttons on a board. Alphabets, numbers, symbols, etc. are printed on these keys. By pressing these keys, text or instructions are inputted into the computer. Although, the number of keys can vary in different keyboards, yet when it comes to a simple keyboard, it comes in two different sizes – with and without a numeric keypad. Keyboards without a numeric keypad have 83, 84, or 86 keys, while keyboards with a numeric keypad have 101, 102, 104, or 108 keys.
The mouse is a small pointing device that is similar in size to the real mouse. Like the keyboard, the mouse is also available in both wired and wireless variants. It has generally two buttons called the left and right buttons. The left button is used to select an object or option by pressing it or clicking. While pressing the right button or right-clicking opens a shortcut menu. There is also a wheel between these two buttons, which can be scrolled up and down a page slowly by rotating. The same thing can be done by pressing the wheel.
The mouse is designed to be easily held between the fingers and the palm. By moving it in any direction on a flat surface, the pointer also starts moving in the same direction. The old mouse consisted of a rubber-coated metal ball at the bottom, which rotated through the movement of the mouse on the flat surface. The movement of the pointer was caused by the movement of this ball. Such kinds of mouse are called mechanical mouse. In the new mouse, LED lights and optical sensors are used instead of balls to detect the movement. Such a mouse is called an optical mouse.
Apart from these, there are many types of mouse available in the market such as a vertical mouse, air mouse, laser mouse, and even foot mouse.
The trackball is also a pointing device similar to a mouse. It has a ball like the old mechanical mouse. The pointer can be controlled by rolling the ball. But unlike the mechanical mouse, it is fitted on the top side instead of the bottom. Due to the ball being placed upside, it is very convenient to use without moving the hand. Trackballs also have buttons for left and right-click.
Touchpad or Trackpad
The touchpad or trackpad is also a pointing device. It is used instead of the mouse in portable computers like laptops. It is a rectangular plate that resides in the middle of the palm rest under the keyboard. The pointer can be controlled by moving the fingers on its flat surface. It also has two buttons that function like mouse buttons.
The joystick is mostly used in playing video games. Apart from this, it is also used in plane simulators, unmanned vehicles, CCTV, etc. It has two parts, a vertical handle, and a base. One end of the handle is pivot in the base and its other end is kept free. By holding the handle and tilting it in any direction, the pointer or object also starts moving in the same direction. There are also some buttons on its handle and base which can be programmed for different tasks.
In the old times, documents were stored in hard copy. Which were very difficult to protect them for a long time due to wear and tear, moisture, loss, etc., to move them from one place to another, copying them, etc. Thanks to the scanner, which is an input device that produces a digital copy of the paper, document, or object. Which can be saved on a computer as an image or pdf document. It is much easier to preserve a scanned copy than a hard copy. They can be sent anywhere in a moment through the Internet. Moreover, they can be easily printed to produce more copies.
A webcam is a small video camera that can capture images or videos. The computer can stream these captured images or live video to the internet in realtime. That is why a webcam is mostly used for video chatting, conference, or CCTV. Most webcams are connected to computers with a USB, firewire, or wireless connection. Portable computers such as laptops, tablets, and mobile phones have inbuilt web camera setup. Such cameras are located nearby the screen or backside of the devices or in both places.
A microphone or mic is an input device that gives audio input to the computer. It captures audio by converting sound waves into electric signals which may be analog or digital. It is mostly used in recording, audio-video conferences, chatting, etc. Apart from this, voice commands are also available in many new operating systems and application software. Such computers can be operated by speaking commands.
Apart from all these devices, many other input devices might be connected to the computer as per the requirement. Which include fingerprint readers, retinal scanners, optical mark readers (OMR), optical character readers (OCR), magnetic ink character recognition (MICR), bar code and QR code readers, etc.