Computer is an electronic device that works with information. The term computer has been derived from the Latin word “computare”, which means computing or arithmetic. The computer cannot do anything without a program, which is a set of instructions to perform a particular task.
The word “computer” was originally used for human computers (humans) who did numerical calculations with the help of mechanical calculators, like abacus. The term “computer” was later given to mechanical device when they started swapping the human computers. Modern computers are electronic devices that receive data (as input), process data, give output, and store the output.
The computer receives raw data (input) from the user, processes the raw data according to some set of instructions called “program”, and gives the result (output) and stores the output for the future use. Computers are capable of processing both numerical and non-numerical calculations.
- Input/Output Device
- Central Processor Unit (CPU)
- Mass storage device
Charles Babbage: Father of Computing
Charles Babbage was considered as the father of computing or as Grand father of the computer after his invention of the first mechanical computer “Analytical Engine” in the year 1837. The Analytical Engine included an Arithmetic Logic Unit (ALU), integrated memory, and basic flow control and used ROM (read-only memory) as punch cards.
Classification of Computers:
Computers are classified based on their data processing abilities, functionality, size, and purpose.
According to purpose, computers are classified as general purpose or specific purpose.
- General purpose computers:
These computers can store numerous programs, but they lack in speed and efficiency.
- Specific purpose computers:
These computers are designed to perform a specific task or to handle a specific problem. A set of instructions is built into the machine.
Based on functionality data handling computers are classified as:
- Analog Computer:
These computers use continuous physical phenomena such as mechanical, electrical or hydraulic to model the problem to be solved.
- Digital Computer:
These computers perform logical operations and calculations with data represented as digits, usually in the binary number system.
- Hybrid Computer (A combination of Analog and Digital)
Hybrid computers are a combination of digital and analog computers. These are capable of processing both digital and analog signals.
Based on size computers are classified as:
Minicomputer is a midsized computer, which lies between mainframes and workstations, in terms of size and power. Minicomputer is a multiprocessing system that supports 4 to 200 users simultaneously.
It’s large in size and expensive computer capable of running an entire corporation. Mainframes are more considered powerful than supercomputers as they support a large number of simultaneous programs. But when it comes to single program execution, supercomputers are faster than a mainframe.
Supercomputers are the fastest and most powerful computers on Earth, as well as most expensive. These are for specialised applications that require enormous amounts of mathematical calculations. These computers are also used for nuclear energy research, animated graphics, fluid dynamic calculations and petroleum exploration.
The main difference between a mainframe and supercomputer is that a mainframe computer uses its power to execute a lot of programs concurrently, whereas supercomputer uses all its power to execute a few programs as quickly as possible.
- Microcomputer or Personal computer:
The microcomputer is a small and low-cost computer. Microcomputers or personal computers include desktop, laptop, notebooks etc.
The workstation is a name given to a network of desktop computers. The workstation is a name given to client machine in contrast to a “mainframe” or “server”.