Basics of Computers - Introduction
Being
a modern-day kid you must have used, seen, or read about computers. This is
because they are an integral part of our everyday existence. Be it school,
banks, shops, railway stations, hospital or your own home, computers are
present everywhere, making our work easier and faster for us. As they are such
integral parts of our lives, we must know what they are and how they function.
Let us start with defining the term computer formally.
The
literal meaning of computer is a device that can calculate. However, modern
computers can do a lot more than calculate. Computer is an electronic
device that receives input, stores or processes the input as per user
instructions and provides output in desired format.
Input-Process-Output Model
Computer
input is called data and the output obtained after processing it,
based on user’s instructions is called information. Raw facts and figures
which can be processed using arithmetic and logical operations to obtain
information are called data.
The
processes that can be applied to data are of two types −
· Arithmetic operations − Examples include calculations like addition,
subtraction, differentials, square root, etc.
- Logical operations − Examples include comparison operations
like greater than, less than, equal to, opposite, etc.
The
corresponding figure for an actual computer looks something like this −
The
basic parts of a computer are as follows −
· Input Unit − Devices like keyboard and mouse that are
used to input data and instructions to the computer are called input unit.
· Output Unit − Devices like printer and visual display unit
that are used to provide information to the user in desired format are called
output unit.
· Control Unit − As the name suggests, this unit controls all
the functions of the computer. All devices or parts of computer interact
through the control unit.
· Arithmetic Logic Unit − This is the brain of the computer where all
arithmetic operations and logical operations take place.
· Memory − All input data, instructions and data
interim to the processes are stored in the memory. Memory is of two types
– primary memory and secondary memory. Primary memory resides
within the CPU whereas secondary memory is external to it.
Control
unit, arithmetic logic unit and memory are together called the central
processing unit or CPU. Computer devices like keyboard, mouse,
printer, etc. that we can see and touch are the hardware components
of a computer. The set of instructions or programs that make the computer
function using these hardware parts are called software. We cannot see or
touch software. Both hardware and software are necessary for working of a
computer.
Characteristics of Computer
To
understand why computers are such an important part of our lives, let us look
at some of its characteristics −
· Speed − Typically, a computer can carry out 3-4
million instructions per second.
· Accuracy − Computers exhibit a very high degree of
accuracy. Errors that may occur are usually due to inaccurate data, wrong
instructions or bug in chips – all human errors.
· Reliability − Computers can carry out same type of work
repeatedly without throwing up errors due to tiredness or boredom, which are
very common among humans.
· Versatility − Computers can carry out a wide range of work
from data entry and ticket booking to complex mathematical calculations and
continuous astronomical observations. If you can input the necessary data with
correct instructions, computer will do the processing.
· Storage Capacity − Computers can store a very large amount of
data at a fraction of cost of traditional storage of files. Also, data is safe
from normal wear and tear associated with paper.
Advantages of Using Computer
Now
that we know the characteristics of computers, we can see the advantages that
computers offer−
· Computers
can do the same task repetitively with same accuracy.
· Computers
do not get tired or bored.
· Computers
can take up routine tasks while releasing human resource for more intelligent
functions.
Disadvantages of Using Computer
Despite
so many advantages, computers have some disadvantages of their own −
· Computers
have no intelligence; they follow the instructions blindly without considering
the outcome.
· Regular
electric supply is necessary to make computers work, which could prove
difficult everywhere especially in developing nations.
Booting
Starting
a computer or a computer-embedded device is called booting. Booting takes
place in two steps −
- Switching on
power supply
- Loading
operating system into computer’s main memory
- Keeping all
applications in a state of readiness in case needed by the user
The
first program or set of instructions that run when the computer is switched on
is called BIOS or Basic Input Output System. BIOS is a firmware,
i.e. a piece of software permanently programmed into the hardware.
If a
system is already running but needs to be restarted, it is called rebooting.
Rebooting may be required if a software or hardware has been installed or
system is unusually slow.
There
are two types of booting −
· Cold Booting − When the system is started by switching on
the power supply it is called cold booting. The next step in cold booting is
loading of BIOS.
· Warm Booting − When the system is already running and needs
to be restarted or rebooted, it is called warm booting. Warm booting is faster
than cold booting because BIOS is not reloaded.
