What is Computer?

A computer is a programmable electronic device that accepts raw data as input and processes it with a  set of instructions (a program) to produce the result as output.

The term "computer" is derived from the Latin word "computare" which means to calculate.

It is believed that theAnalytical Engine was the first computer which was invented by Charles Babbage
in 1837. Charles Babbage is also known as the father of the computer.

There are 5 main computer components that are given below:

• Input Devices
• CPU
• Output Devices
• Primary Memory
• Secondary Memory

 Inputting: It is the process of entering raw data, instructions and information into the computer.              It is performed with the help of input devices.

Storing: The computer has primary memory and secondary storage to store data and instructions. It stores the data before sending it to CPU for processing and also stores the processed data before displaying it as output.

Processing: It is the process of converting the raw data into useful information. This process is performed by the CPU of the computer. It takes the raw data from storage, processes it and then sends back the processed data to storage.

Outputting: It is the process of presenting the processed data through output devices like monitor, printer and speakers.

Controlling: This operation is performed by the control unit that is part of CPU. The control unit ensures that all basic operations are executed in a right manner and sequence.

Central Processing Unit (CPU)

A Central ProcessingUnit is also called a processor, central processor, or microprocessor. It carries out all the important functions of a computer. It receives instructions from both the hardware and active software and produces output accordingly.

Generally, a CPU has three components:

• ALU (Arithmetic Logic Unit)
• Control Unit
• Memory or Storage Unit

Control Unit: It is the circuitry in the control unit, which makes use of electrical signals to instruct the computer system for executing already stored instructions. It takes instructions from memory and then decodes and executes these instructions. So, it controls and coordinates the functioning of all parts of the computer. The Control Unit's main task is to maintain and regulate the flow of information across the processor. It does not take part in processing and storing data.

ALU: It is the arithmetic logic unit, which performs arithmetic and logical functions. Arithmetic functions include addition, subtraction, multiplication division, and comparisons. Logical functions mainly include selecting, comparing, and merging the data. A CPU may contain more than one ALU. Furthermore, ALUs can be used for maintaining timers that help run the computer.

Memory or Storage Unit/ Registers: It is called Random access memory (RAM). It temporarily stores data, programs, and intermediate and final results of processing. So, it acts as a temporary storage area that holds the data temporarily, which is used to run the computer.