What is Computer?Explain Block diagram of computer?Explain parts of computer?

What is Computer?

Computer is an electronic device which is used for storing data, processes the data as per given instruction, and providing the necessary information. In short, Computer is a programmable machine. Computer is derived from the Latin word “computare” which means to process or calculate.

Computer takes input in form of raw data, carries arithmetic and logical operations on that data as per instructions, and provides the output information via output devices.

Modern computers have the ability to follow generalized sets of operations, called programs. These programs enable computers to perform an extremely wide range of tasks.

Two things combine to form a complete computer. They are:

1. Computer Hardware:

Computer Hardware includes all the physical parts of the computer like CPU, Monitor, Keyboard, Mouse, Speaker, Printer, Scanner, etc. All the tangible parts of computer can be called hardware part of computer.

2. Computer Software:

Computer Software includes programs (i.e. set of instructions) that tells hardware parts what and how to operate. It controls the hardware to perform tasks. Example: Microsoft Word to write a document, PowerPoint to create a presentation, etc.

Block Diagram of Computer

Figure 1: Block Diagram of Computer

The block diagram of Computer contains: Input Unit, Output Unit, Memory Unit, CPU (Arithmetic Logic Unit, and Control Unit).

The Input Unit provides the input as raw data to the computer. Input can be collection of letter, number, images, etc. Eg: Joystick, Mouse, Keyboard.

The Output Unit provides the processed data given by the computer output from the computer. Eg: Visual Display Unit, Monitor, Printer.

The Memory Unit stores the data which is to be transferred to the CPU when needed. Eg: RAM, ROM, Hard drive.

Parts of Computer

CPU:

CPU is abbreviation for Central Processing Unit. The CPU is also called the "brain" of the computer because it calculates and manipulates data sent by the user. Each time the user clicks a key, executes an application or browses the Web, the CPU reads the code involved and returns the response to the user. The CPU works closely with memory, which is the component that sends stored data to the unit. It contains following elements:

RAM:

RAM is abbreviation for Random Access Memory. It is the main memory which is directly accessible by CPU.is variable in a computer. Older computers had only a few dozen megabytes of RAM installed. When personal computers became popular in the 1990s, computers had 32 megabytes of memory. Motherboards and software now require at least one gigabyte to function. RAM contains the information during the time the computer is on. After the machine is turned off, the information in RAM is lost.

Hard Drive:

Unlike RAM, the hard drive stores data even after the machine is turned off. A hard drive is the storage unit for the machine. Saved documents and applications are stored on the hard drive using magnetism. The hard drive is made up of small platters with a moving head. The platters spin as the head moves back and forth to retrieve and store data.

Motherboard:

Each component is attached to the motherboard. The motherboard receives power from the computer's power supply. The motherboard allows all the components to communicate, including the CPU. The motherboard also contains controllers, which are circuits that help the operating system work with hardware such as the hard drive.

Input Devices:

Keyboard:

Keyboard is a human interface device which is represented as a layout of buttons. Each button, or key, can be used to either input a linguistic character to a computer, or to call upon a particular function of the computer. They act as the main text entry interface for most users. Traditional keyboards use spring-based buttons, though newer variations employ virtual keys, or even projected keyboards. It is typewriter like device composed of a matrix of switches. There also happens to be another keyboard that is like an input device for musical instrument which helps to produce sound.

Joystick:

A joystick is an input device consisting of a stick that pivots on a base and reports its angle or direction to the device it is controlling. A joystick, also known as the control column, is the principal control device in the cockpit of many civilian and military aircraft, either as a center stick or side-stick. It often has supplementary switches to control various aspects of the aircraft's flight.

Mouse:

Pointing devices are the most commonly used input devices today. A pointing device is any human interface device that allows a user to input spatial data to a computer. In the case of mouse and touchpads, this is usually achieved by detecting movement across a physical surface. Analog devices, such as 3D mice, joysticks, or pointing sticks, function by reporting their angle of deflection.

Output Devices:

Visual Display Unit:

A display device is the most common form of output device. It presents output visually on computer screen. The output appears temporarily on the screen and can easily alter or erased, it is sometimes referred to as soft copy also. The display device for a desktop PC is called monitor.

Printer:

a printer is a peripheral device which makes a persistent representation of graphics or text, usually on paper. While most output is human-readable, bar code printers are an example of an expanded use for printers.