Input operations and output operations
Computers receive input from the user. Inputting is the preliminary operation that is performed on a computer. The input unit performs the input operations. Only after receiving the input the computer can process data that is fetched form the user. Input becomes the mandatory operation of a computer system. Without the input from the user the computers will have no data to work with.
The information is input to the computer through peripheral devices like keyboards, scanners, joysticks and digital cameras. A few input devices, like scanners, send the input information directly to the CPU and they do not need any encoding process. Such peripheral devices are called, Direct Entry Input Devices. Data entered from input devices like keyboards needs to be encoded before the information reaches the central processing unit. Such devices are called Indirect Entry Input Devices. The input data is encoded into bit format. The computer can understand only the bit format. After the processing is done, the result is then decoded into the human understandable format and displayed to the user.
The output operations in the computers are performed by the Output Devices. The output peripherals display information on the monitor of the computer, or they print the information with the help of a printer. The output operations also include displaying error messages, dialog boxes, etc. Sometimes the output devices save the data in the memory of the computer for its future usage. The output operations gain a lot of importance because the user gets his/her final result of the operations only through them. Some examples of the output devices are plotters, speakers, LCD projectors, etc.
Storage, processing, and controlling operations
The storage operations store the information for later usage. Storage operations store the data in a digital format. The data can be fetched form the storage whenever necessary. The computer can store the data temporarily or permanently.
There are two important types of storage devices. They are the Random Access Memory (RAM) and the Read Only Memory (ROM). The RAM is a non-permanent memory and the ROM is a permanent memory. There are also many other storage devices like the Compact Disks (CD), Digital Versatile Disk (DVD), pen drives etc.
The processing operations in the computers happens with the help if the Central Processing Unit. The CPU is also called as the processor. The CPU is basically a chip that has several tiny transistors. The two basic types of operations that are performed by the CPU are the arithmetic and the logical operations.
Examples of arithmetic operations includes subtraction of any two integers and the example of logical operation includes finding the smaller of two numbers. The processing operations retrieve the information from the memory. It manipulates the information into a new form. The BIOS or the Output and Input streams control the communication between various devices. The CPU is called the brain of the computer.
The controlling operations are done by the control unit that is an integral component of the central processing unit.
The control unit controls the data transfer among the several components of the computer. The control unit manages all the other units of the computer.
The control unit gets the appropriate data from the memory and it gives directions to process the information.
The communication between the input and output devices are controlled by the control unit.
The control unit does not process or save the data but, it controls the operations that are happening in the system.
