Computer – Basic operations and Terminologies

I am giving below the very basics of the computer.  In case you already know computers, I am sure you will find this too elementary and may even like to skip.  However, I will still like you to go through this page quickly as there may be one or two points which may add some knowledge / clarification as in the race to learn higher and higher, sometimes we miss even the basics :-

What is a computer ?  Define a Computer ?

A computer is an electronic device, which can compute and process data as per the programmed set inside it.   However, these days the term is mostly used to refer to the “Desktop” and “Laptop” computers  that are used by most of us.   If you have seen inside a computer, you must have noticed that it is not a single part machine.     These machines (Desktop and laptops)  are also popularly known as Personal Computers or PC.   Each computer consists of number of technical parts which are assembled in the required manner.

Broad Categories of Computers :-

1.Based on Uses :

• 1.1 Analog Computer : It measures pressure, temperature, length, etc, of physical quantities and converts into its numerical values. They are mainly used for scientific and engineering purposes.
• 1.2 Digital Computer : It is used in counting of numbers, words or other special symbols. It is also used in fuel control of automobiles and banking processes.
• 1.3 Hybrid Computer : It is the combined form of analog and digital computer. Information is continuously converted into data that are received in the form of input. Output may be in form of analog and digital. They are used in factories and machines.

2. Based on Sizes : computers are also classified based on their size viz :

• 2.1 Micro Computer :  It is the smallest computer in which ALU and CPU are based on the same chip.
• 2.2 Personal Computer : It is single user system used generally in homes and small businesses.  Desktop and Laptops are examples of PCs, as these are best for day to day small operations.
• 2.3 Mini Computer :  It is more powerful than micro computer and can be used by many users at the same time. It processes data very fast.
• 2.4 Main Frame Computer :  They are giant in size and of highly storage capacity. They can process an ample amount of data very rapidly. They are used in banks, large organization and public sectors.
• 2.5 Super Computer :  They are capable of processing the huge amount of data in fraction of seconds. They are used in very complex calculation.

What are the Major Parts of the Computer :-

• Central Processing Unit (popularly known as CPU)  – it consists of different technical parts like processor, motherboard, hard disc, RAM, CD Drive and cabinet with SMPS.
• Monitor
• Keyboard
• Mouse

What are  major accessories of the computer system ?

In addition to the above referred major components of the computer, we find the following accessories attached to most of the computers :-

• Speakers
• Printers
• Scanners
• Modem

Explain the concept of CPU:

Central Processing Unit or CPU is considered  as the brain of computer.   CPU consists of electronic circuits that interpret and execute instructions.  It communicates with the input, output and storage devices.  CPU, with the help of memory, executes instructions in the repetition of machine cycles.  The speed of computer is measured in megahertz, MHz.  A MHz is a million machine cycles per second.  A personal computer of 500 MHz has a processor capable of handling 500 million machine cycles per second.  Another measure of speed is gigahertz (GHz), which means a billion machine cycles per second.

Explain the concept of  Memory – RAM / ROM :

Memory or internal memory or primary storage works with the CPU to hold instructions and data in order to be processed.   It is in the memory that data and instructions are placed after being input.

(a) Moreover, the information is also placed in memory after processing so as to be returned to an output device.   This kind of memory holds data only temporarily till electrical current flow continuously.  If current is interrupted, data is lost.  Random Access memory (popularly known as RAM) is an example of this kind of memory.   Thus, in this memory when we switch off the computer, the data is lost.    The users access data in RAM memory randomly as per needs.  RAM can be erased or written over at will by the computer programme

(b) Another kind of memory is  Read Only Memory (ROM).  It contains prorams and data that are permanently recorded when the computer is manufactured.  It is read only and is used by the processor.  It  is permanent in nature. and can not be altered or deleted by the user.

Thus, we can say that RAM is like a slate where you can write something for immediate reference and then wipe / change data by adding or deleting when it is not needed, but ROM is like a printed book, where once the text is  printed then it cannot be altered.

(c) Secondary memory is also known as external memory or storage.  It consists of Hard Discs,   Floppy Disc (now a days out of fashion) , CDs  and DVDs  as well as pen drives.  External device consists of more storage space and most dynamic in terms of storing data.

Memory is measured in bytes.  A byte is usually made up of 8 bits and represents one character – a letter, digit or symbol.   The number of bytes that can be held is a measure of the memory and storage capacity.   Bytes are usually measured in groups of kilobytes, megabytes, gigabytes and terabytes.

What are the Functions of the major components / accessories of the compute system:-

CPU is the main unit of processing data, a mother borad is an electronic circuit for different functions, hard disc is for storing the data, CD drive is to read and write data on CDs (compact discs).   Monitor is for displaying the data, and is also popularly known as screen or display unit.  Keyboard is used to input the data.   Mouse is a pointing or selection unit.  Speakers, we all  know, are used to hear the sound / music.  Printer is used to take the print of the data from the computer system.  Scanner is used to scan and then store the image / pictures in the computer.  Modem is used to connect to internet.

I hope you have been able to pick up few new concepts and explanations.