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Computer is the lifeline of modern day civilization - Computer essay introduction. One can not even think of life without computer today. It has become a day to day need for each and every individual. Life of even those who are not using or even have not seen a computer is so heavily dependent on computer, that everything will become practically standstill once we remove computers from the society. It is therefore, only natural that we understand this wonderful machine called computer. What is a computer? Computer literally means a person or a device which can do computing. But then anybody can do computing and we do not call everybody a Computer. The fact that anybody can do computing can be explained by the fact that the human brain is a very good computer. So, what is a computer? It is now a days no longer tough to define it. The way we perceive computers today is an electronic machine that does a lot of fantastic work. How it do so? First of all let us define COMPUTER.
A Computer is a machine which is used for manipulating data according to a list of instructions. It can also be defined as: A programmable machine having two principal characteristics:
which responds to a specific set of instructions and
which can execute a prerecorded list of instructions.
Hence, a computer can be defined as an electronic data processing device, capable of accepting data, applying a prescribed set of instructions to the data, and displaying in some manner or form. Therefore, it has a means to accept data by using input devices; it has a processor to processor to process the data as per the set of given instructions also termed a program, and a means to display data by means of an output devices. We will talk about all this, but lets begin with history of computers.
The History of Computers:
Who invented computer? It is not simple to answer the question. The answer to the question is that many inventors contributed to the evolution of modern day computers
Primitive examples of mechanical calculating devices like Abacus (http://en.wikipedia.org/wiki/Abacus), Slide rule http://en.wikipedia.org/wiki/Slide_rule
and Antikythera mechanisms (http://www.math.sunysb.edu/~tony/whatsnew/column/antikytheraI-0400/kyth1.html) can be considered as initial computing devices. In 1837 Charles Babbage coceptualized and designed a fully programmable machinery which was termed as The Computer (http://en.wikipedia.org/wiki/computer), it was essentially a mechanical computer. By the end of 19th century a number of technologies had begun to appear which proved useful in the realization of practical computers.Many new advancements were done during the first half of 20th century and more powerful and flexible computing devices were constructed in 1930s and 1940s.Vacuum-tube based computers were in use throughout the 1950s but they were largely replaced in the 1960s by transistor-based devices.The transistor-based devices proved to be cheaper,smaller,faster.They used less power and were more reliable.By the 1980s,computers had become sufficiently small and became widely accessible for personal use,now popularly known as Personal Computers.
Components of a Computer:
Today the computers we use are electronic and digital. To know the basic components and working of a computer,we can divide the computer into two basic parts:The hardware and The software part. The hardware parts include the transistors and other electronic components on the printed circuit board to make the circuits. The software part includes the instructions and data required to perform the operations.
Modern computers require the following hardware components:
Memory: It enables the computer to store data and programs.It is the most important hardware component as during execution the data is fetched from the memory.There are several different types of memory:
RAM(random-access memory):It is referred to as the main memory.We can both write data into RAM and read data from RAM.It is a volatile memory as it loses the data when the power is turned off.
ROM(read-only memory):It permits only to read from it.It holds the instructions for starting up the computer.It is a non-volatile memory.
PROM(programmable read-only memory):It is a memory used to store a program only once.
EPROM(erasable programmable read-only memory):It is a special type of PROM that can be erased by exposing it to ultraviolet light.
EEPROM(electrically erasable programmable read-only memory):It is a special type of PROM that can be erased by exposing it to an electrical charge.
Input/Output device:The input device is the medium through which data and instruction enter the computer.The typical devices are keyboard and mouse.
The output device is the display screen,printer which shows what the computer has performed.
CPU(central processing unit):It is called the heart of the computer.It is actually the main processing unit where all the instructions are executed.Actually all the hardware components are assembled to make a CPU.
The software part refers to the programs,data,protocols.The software is the collection of instructions which is stored on the hardware for the working of the computer.The operating system is the basic software that allows the user to interface with the computer.The operating system is the first thing loaded onto the computer.Without the operating system a computer is useless.The purpose of an operating system is to organize and control hardware and software so that the device it lives in behaves in a flexible but predictable way.
How do computers work?
To understand the working of a personal computer one has to understand the four main sections.They contribute to the working of a computer.They are arithmetic and logic unit(ALU),the control unit,the memory,and the input and output devices.These are interconnected by busses,which are a group of wires.The ALU,the control unit and the memory collectively constitute the CPU(central processing unit).The CPU is nothing but the microprocessor which controls how data is sorted and directs the flow of data.
The ALU is capable of performing arithmetic and logical operations.The arithmetic operation involves the addition,subtraction,multiplication,etc.while the logical operation involves the boolean logic which can be useful for creating complicated conditional statements and processing boolean logic.
The control unit reads and interprets the instructions in the program.It decodes each instruction and turns it into a series of control signals that operate the other parts of the computer.
The memory is used to read or write data to it.When ever the ALU has to perform any operation, it fetches data from the memory or it writes into the memory.The CPU also contains a special set of memory cells called registers.These can be read and written to much more rapidly reducing the need to access the main memory area contributing to the increased speed of the computer.
The input and output device is the means by which computers receives informationfrom the outside world and sends results back.
Types of Computers:The computers can be classified by their size and power.The different types of computers are:
Personal computer:It is a small,single user computer. It has evolved very rapidly in past two decades in terms of processor speed, memory, storage size, imput and output devices and simultaneously the cost has decreased considerably. Today, powerful PCs have becomes affordable even in developing nation and are contributing to their economies in a big way, where PC penetration has led to a large pool of software professionals.
Workstation:A workstation is like a personal computer but it uses a more powerful microprocessor and a higher quality monitor.
Minicomputer:It is a multi-user computer.It can support from 10 to hundreds of users simultaneously.
Mainframe:It is a powerful multi user computer capable of supporting hundreds to thousands of users simultaneously.
Supercomputer:It is an extremely fast computer. The reason for Supercomputers to be fast is the fact that they have a large number of processors working parallely. It can perform hundreds of millions of instructions in a single second. Such computers are very useful in analyzing a very large pool of data, required for doing calculations in very complex situations like weather forecasting etc. Due to these reasons, these are of dual use nature and are under export embargos.
The computer has become one of the most predominant electronic device to come out of the field of technology.The contribution of computers in our lives are of great value.It has helped us in our home,businesses and government sects of society. One of the most important use of computers is in accessing internet.Internet in an interconnection of networks.It is a collection of services and resources.One can get in touch with the world through the advent of Internet.These are the various fields in which the computers are applicable:Health and medicine,Home,ScientificResearch,Education,Businesses,Transportation,Banking,etc. Hence, Computers are very productive, efficient and make our personal and professional lives more rewarding.It has become a part and parcel of our life.Ultimately they can be called as a mainstay in today’s society.
The Computer Era,what we call today, glows before us with the promise of new and improved ways of thinking, living and working. It has revolutionised the way one does his job or an organization operates their businesses. Together with this reason and many more, computers are considered more than just an essential piece of fancy equipment. Irrespective of what people know anything about it, they invoke computers in every day lives. Today we can find computers all around us and avoiding them has become practically impossible.
Therefore, it can be said that computers have become the part and parcel of modernday civilization and are of are indispensible in our life.