Subject – Fundamentals of Computer Science
Unit -1
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.
Unit -1
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.
