A computer is a machine capable of complex calculations at high speed. Today it seems that almost every device is a computer. A computer is a combination of hardware and software. It has several components, and include the monitor, the processor chassis, mouse and keyboard. The components of a computer :

Computer Monitor
The monitor is a device used by the computer for text and images. A few years ago, almost any computer monitor using a cathode-ray tube. But today, the flat panel display systems are becoming increasingly popular.

Keyboard
Keyboard is an input device to receive data into the computer. There are many keyboard models.

Mouse
The mouse is an input device used to ‘and click. In the days of DOS operating system, it is possible to use a computer without a mouse. But the advent of the graphical user interface, the mouse has a very important input device.

The CPU Chassis
The chassis or CPU CPU case the houses hard disk and other hardware components such as hard drives, motherboard etc.

Hardware
One of the hardware components are the elements that you can see and touch. The smallest of the hardware components of a computer is a chip. A computer chip is composed of layers of son and semiconductors. Semi-conductors in a chip to be configured either a 0 or 1 January as electricity through them. The hardware includes a computer motherboard, Basic Input Output System (BIOS), Central Processing Unit (CPU), memory (RAM), disk drives, Sound Processor, Video Processor, diskettes, hard disks, CD -ROM, DVD – ROM and maps.

Computer Software
The software is a set of instructions that tell the computer how to process, store and retrieve data. The software is basically of two types: operating systems and applications.

Operating Systems
An operating system is a type of software used to operate the computer. It gives us an interface that can execute commands to the computer. There are different types of operating systems. Examples: Windows, Linux, Unix and DOS. The Windows operating system built by Microsoft is the most popular operating system used today. Macintosh computers use the Mac OS X and OS operating systems built by Apple Computers.

Applications
An application is a software that is installed on the computer, and then executed by the processor of the computer. The application allows users to interact with the computer so they can do or processing data or performing a specific task. Examples of applications are text editors, word processors, spreadsheets, web browsers and email clients.

A text editor is an application allowing the user to create text files. A word processor is an advanced text editor. Spreadsheets allows users to create tables and columns of numbers and figures. With a spreadsheet, you can perform calculations on numbers. An e-mail client is an application that can connect to an e-mail server to receive or send an e-mail. Most e-mail clients available today are very advanced applications such as functions of spell checkers. A Web browser is an application that allows you to access information on the Internet. Examples: Mozilla Fire Fox, Microsoft Internet Explorer, Safari and Opera.