PROCESSOR

The Central Processing Unit (CPU) ,also called a processor , is like the brain of the computer. It executes instructions given by a user or an application . The processor's speed is measured in megahertz (MHz) or gigahertz(GHz). The higher the speed , the faster the execution of instructions.

PRIMARY MEMORY

RAM (Random Access Memory) is also called the main memory . RAM is used to store data and instructions that are currently being processed by a computer's CPU . Data is temporarily stored in the RAM till it is stored in the hard disk . The data in the RAM is erased when the power is switched off.

SECONDARY MEMORY

Secondary Memory is the memory where the information is stored permanently till it is explicitly deleted . Information is moved between main memory and secondary memory as and when needed . The data on the hard disk and other secondary storage devices does not get erased even after switching off the computer. CD/DVD, external hard disk drive ,SD card , and pen drive are removable storage devices . these can be used to take backup of important data . They are also used to distribute and share information or transfer information from one computer to another.

INPUT DEVICES

An input device converts data and instructions to a pattern of electrical signals . These signals corrrespond to a binary code that can be processed by a digital computer.

OUTPUT DEVICES

An output device reverses the process , translating the binary code into a form understandable by the user . The computer displays processed information , for example , a printout of the information , an audio , a video , etc., through the output devices .

OPERATING SYSTEMS

The operating system (OS) is responsible for managing a computer's hardware and software resources . It controls the memory needed for the computer processes , the hard disk space , the peripheral devices , and user communication with the computer. The operating system loads at the end of booting process . From this point , it controls the way in which the computer functions .