Introduction to Computer

Pronunciation: com-put-er

Definition: A computer is a programmable machine that receives input, stores and manipulates data, and provides output in an expected format.

Brief: A computer was invented to make human life simpler. User provides problem to the use in terms of a set of instructions, computer executes it and provides user a solution. Instructions are nothing but sequence of arithmetic or logical operations. The particular sequence of operations can be changed readily, allowing the computer to solve more than one kind of problem.

A typical computer consists of following components:

·         Memory: Enables a computer to store temporarily data and programs.

·         Mass storage device: Allows a computer to permanently retain large amounts of data. Common mass storage devices include disk and tape drives.

·         Input device: Usually a keyboard and mouse, the input device through which data and instructions enter a computer.

·         Output device: A display screen, printer, or other device that lets you see what the computer has processed.

·         Central processing unit (CPU): The heart of the computer, this is the component that actually executes instructions.

Conventionally a computer consists of some form of memory for data storage, at least one element that carries out arithmetic and logic operations, and a sequencing & control element that can change the order of operations based on the information that is stored. Peripheral devices allow information to be entered from external source, and allow the results of operations to be sent out.

A computer's processing unit executes series of instructions that make it read, manipulate and then store data. Conditional instructions change the sequence of instructions as a function of the current state of the machine or its environment.

 

Computers are classified by size and power as follows:

·         Personal computer: A small, single-user computer based on a microprocessor. In addition to the microprocessor, a personal computer has a keyboard for entering data, a monitor for displaying information, and a storage device for saving data. For e.g., a normal Laptop/Desktop we use in our day today life.

·         Workstation: A powerful, single-user computer. A workstation is like a personal computer, but it has a more powerful microprocessor and a higher-quality monitor. A workstation is a personal computer that is used for high end applications such as graphic design, video editing, CAD, 3-D design, or other CPU and RAM intensive programs. A workstation typically has a top of the line, fast processor, multiple hard drives, and a lot of RAM memory. A workstation may also have special audio, video, or processing cards for special editing work. A workstation is marketed by computer manufacturers to professional users, while the server is more of a utility device.

·         Minicomputer: A multi-user computer capable of supporting from 10 to hundreds of users simultaneously. A midsized computer. In size and power, minicomputers lie between workstations and mainframes.

·         Mainframe: A powerful multi-user computer capable of supporting many hundreds or thousands of users simultaneously. These computers are used where robustness is expected and continuous processing is required. For e.g., India railway uses mainframe computers to stores travelers information.

·         Supercomputer: An extremely fast computer that can perform hundreds of millions of instructions per second. Mainly used in the Research and Development activities requiring maximum accuracy, faster output and complex solutions. For e.g., Airline system, Launching & controlling satellites, researching on new medicines etc.

Hope the information turns useful for you.