Assignment on A Personal Computer

A computer is an electronic machine that stores ,retrieves and processes data .it can not think or reason ;it can only carryout instructions given to it..A computer is an universal information manipulator. More technically we can define computer as an electronic machine capable of solving problems by processing or manipulating information according to instructions that have been given to it .computers are very powerful and cheap enough to do many task such as: video conferencing, animations, speech processing e.t.c.

Computer is a wondering device of modern age. It has changed our life dramatically. It is like a magic box. We just can’t imagine our day without this magic box. It is now quite expected to one that a man must ours a computer.

Computer is such an electronic device that process data and convert those into information.
Personal Computer Definition: A device that computes, especially a programmable electronic machine that performs high-speed mathematical or logical operations or that assembles, stores, correlates, or otherwise processes information. A personal computer contrasted with the batch processing or time-sharing models which allowed larger, more expensive minicomputer and mainframe systems to be used by many people, usually at the sometime.
A computer is a machine that can be programmed to manipulate symbols. Its principal characteristics are:
It responds to a specific set of instructions in a well-defined manner.
It can execute a prerecorded list of instructions .
It can quickly store and retrieve large amounts of data.

Therefore computers can perform complex and repetitive procedures quickly, precisely and reliably. Modern computers are electronic and digital. The actual machinery is called hardware; the instructions and data are called software. All general-purpose computers require the following hardware components:

Classification of Computers
Based on the operational principle of computers, they are categorized as analog, digital and hybrid computers.

Operational Principle
Analog Computers: These are almost extinct today. These are different from a digital computer because an analog computer can perform several mathematical operations simultaneously. It uses continuous variables for mathematical operations and utilizes mechanical or electrical energy.
Digital Computers: They use digital circuits and are designed to operate on two states, namely bits 0 and 1. They are analogous to states ON and OFF. Data on these computers is represented as a series of 0s and 1s. Digital computers are suitable for complex computation and have higher processing speeds. They are programmable. Digital computers are either general purpose computers or special purpose ones. General purpose computers, as their name suggests, are designed for specific types of data processing while general purpose computers are meant for general use.

Hybrid Computers: These computers are a combination of both digital and analog computers. In this type of computers, the digital segments perform process control by conversion of analog signals to digital ones.

This was the classification of computers based on their style of functioning. Following is a classification of the different types of computers based on their sizes and processing powers.

Processing Power

Mainframe Computers: Large organizations use mainframes for highly critical applications such as bulk data processing and ERP. Most of the mainframe computers have capacities to host multiple operating systems and operate as a number of virtual machines. They can substitute for several small servers.

Microcomputers: A computer with a microprocessor and its central processing unit is known as a microcomputer. They do not occupy space as much as mainframes do. When supplemented with a keyboard and a mouse, microcomputers can be called personal computers. A monitor, a keyboard and other similar input-output devices, computer memory in the form of RAM and a power supply unit come packaged in a microcomputer. These computers can fit on desks or tables and prove to be the best choice for single-user tasks.