Feaures of computer

1. COMP1116-Applications of ICT
Lecture # 02 Computer – The Features
Instructor: Dr. Aftab Akram (PhD CS)
Assistant Professor
BSCS/ BSIT Semester 1

2. Computer – Inspiration &
Features
• Computer is a machine that was inspired by Human
Brain
• Similar to Human Brain, the purpose of the Computer
was to build a machine that can perform calculations
and processing
• But, faster and accurately
• Most often comparison is made between Human Brain
and the Computer
• So many factors related to human ability are used to
draw a comparison between human and computer

3. SPEED
oComputer is a very high speed electronic device
i.e. it can perform tasks at very high rate
oIt can do complex calculation in fractions of
seconds which human can take even years to
complete
oA computer can process millions or even billions
of instructions in a second
oFor example, human brain can take 40,000
instructions per second while computer can take
upto 140,000 millions or more instructions
oHuman brain transmits binary pulses (signals)
ten billions times slower than a computer
oWhereas inside computer electronic pulses
almost travel with the speed of light

4. ACCURACY
oComputers are highly accurate even then they work
at very high speed
oComputers are 100% accurate machines
o The logic gates which are basic building blocks of
processing inside the Computer are carefully designed
and tested
oIt is almost impossible that any computation or
processing by the Computer is wrong
oHuman can make errors if they work quickly
oIf computer make any error it is due to some
human error which they make during programming

5. CONSISTANCY
oComputers are highly consistent machines
o Because the electronic circuit inside the computer
cannot be changed
o Once built and tested, the circuitry last till computer is
working
oThey can work at high speeds very accurately again
and again without any error
oHuman are prone to errors, if they perform a task
accurately once chances of error increase next time
oComputers on the other hand perform the same
task accurately again and again

6. DATA STORAGE
o Storage capacity of computers is very high
o It can store large amount of data on a very small place
o In case of more need of storage, more devices can be
added very easily to extend storage capacity of
computer
o Moreover, the prices of storage devices are decreasing
day by day, which makes it even convenient to extend
storage capacity
o Whereas human brain storage capacity is very low, it
tends to lose data when new data is stored in it.
o Estimated storage capacity of human brain is 2.5
PetaBytes (equivalent of 3 millions hours of TV shows)

7. MEMORY-Power of Remembrance
o 100% power of remembrance
o Computer storage devices are extremely reliable, i.e., 0.9%
failure rate in one year (only 9 disks will fail in 1000 if used for
24 hours for a whole year)
o Which makes them very reliable for storing data for longer
periods of time
o A man can forget as the time passes
o Computer never forgets
o It would produce the data stored in it whenever
recalled
o It will never say “Sorry I forgot”

8. AUTOMATION
oComputer can work automatically
oOnce instructions are stored in its Memory, it can
work according to these instructions
oNo need to tell him again and again what to do next
oProgramming Languages have been developed to
write Software (or programs) for the computers
oLearning Programing Languages is easy
oMoreover, no-code tools are available which can be
used to write Software without writing any code
o“instructions have to be provided to computer, it
cannot generate instructions by it self”

9. ACTIVENESS
oComputer is a machine, it barely has moving parts
oComputers can work for longer hours
oMainframe Computers have downtime of 0%,
which means they never shutdown
oIf correct conditions are available, a zero value of
Mean Time to Failure (MTTF) can be achieved
oComputers do not feel tiredness and carelessness
oHuman lose concentration when they work for long
hours they need rest and recreation
oComputers never demand rest or show laziness

10. Multitasking
oCPU processes instructions sequentially
oIn old single core processors, it can switch between
tasks rapidly
oGiving an impression of performing multiple task at
a time
oHowever, today multi core processors are available,
which have the ability to processes multiple
instructions at a time
oHuman can concentrate only at one task at a time
oComputer can do multiple task with same accuracy
oHowever, speed can be affected due multiple tasks

11. VERSATILITY
oComputer’s enormous speed, memory and
accuracy has made it most popular machine
oDue to programmability, it can do a variety of jobs
oMost of machines have limited use they can only be
used for specific purpose
oComputer is only machine that is used in vast
conditions and circumstances
oIt can be used to convert any machine intelligent by
controlling its functions
oWe see many such example around us, e.g.,
automobiles, airplanes, etc.

12. Limitations of Computers
• Lack of Intelligence
o Although, Computer’s CPU is thought of similar to
human brain, but it does not have conscious
o It cannot think it self
o Computer works under the control of instructions that
has been given to it by human
o If any error occurs during its working it cannot detect
and correct it, it would simple stop running or would
produce incorrect results
o However, some modern computers have Artificial
Intelligence ability, i.e., they can simulate intelligence
through programming
o But their intelligence is much more simpler than human
intelligence

13. Limitations of Computers
• Lack of senses
o Computer has no senses
o It can only do predefined jobs
o It cannot jump instructions without executing them
o It has to execute instructions whether right or wrong
o It also cannot learn from its experience
o Exceptions: Robots are computers that have senses.
They can see, listen some can even smell or taste.