1. CHARACTERISTICS AND LIMITATIONS OF
COMPUTERS
There are many kinds of computers in the world today but their basic functions are usually the same
and hence, the competition is stiff. We might find it easy to adjust
to a person who has contracted some incurable deformity, but a computer with irreparable deformity
of malfunctions becomes an outdated and useless machine, which is subsequently pushed
aside and ignored for some better machine. If the thinking, talking and reasoning powers make a
human being different from other living creatures, what makes a Computer so special?
Let us first compare the computer with another similar but less versatile calculating
machine viz-the Calculator. Almost all of us have seen a calculator, if not a computer. They are used
extensively at any place dealing with a fair amount of calculations.
CALCULATOR COMPUTER
1. Electronic/Mechanical. 1. Electronic/Automatic.
2. Performs mathematical
calculations
only.
2. Performs mathematical and
logical operations.
3. Operates at a high speed. 3. Operates at an incredibly high speed.
4. Small temporary memory. 4. Large temporary memory.
5. No facility for a secondary storage
device.
5. Facility for large secondary storage
devices.
6. Needs an operator continuously. 6. Once initiated, is capable of functioning
automatically.
7. Handles small and uncomplicated
calculations.
7. Handles volumes of simple and highly
complex operations.
CHARACTERISTICS OF A COMPUTER
So we see, that to define a computer merely as a calculating device is to ignore 80% of
its functional capabilities which include non-mathematical and non-numeric operation
as well. The major characteristics that make the computer such a powerful machine can
be enumerated as speed, storage, accuracy, ability to operate automatically, diligence, scientific
approach, versatility and connectivity and networking. Let us look at each of these characteristics
briefly:-
SPEED
Just as we can measure the speed of moving device e.g. a car traveling in terms of
Km/hours or Miles/hours, the speed of a computer too can be measured.
This speed however is incredibly faster than what man can possibly record or calculate normally. The
computer’s speed at performing a single operation can be measured in terms of milliseconds (A
thousandth of a second or 10-3
), microseconds (A millionth of a second or 10-6
), nanoseconds (A
thousand millionth of a second or 10-9
), picoseconds (A million millionth of second or 10-12
).

2. They are also mentioned sometime as Kilo Instructions Per Second (KIPS),
Million Instructions Per Second (MIPS) and Trillion Instructions Per Second
(TIPS), etc. Further, the most popularly used units of speed in Personal Computers
are MHz and GHz (i.e. related to clock frequency).
STORAGE
One of man’s failings is perhaps his inability to remember and ‘store’ large volumes of
Information is his brain. The computer is capable of overriding this deficiency as it can
store
a) Larger volumes of information being processed simultaneously within its own
temporary memory, and
b) larger volumes of data to be maintained more permanently on secondary media, such
as – floppy disks, magnetic disks and tapes, punched cards, microfilms, Hard Disks,
Mini Hard Disks (external), CD-ROMs, DVD-ROMs, Pen Drives, Zip Drives, MO
Drives. etc.
The storage capacity of any media or item can be measured in terms of certain units.
e.g. a 1 litre bottle or a 5kg sack or a 1500 cubic litre water tank etc. The storage
capacity of a computer is measured in terms of Bytes, Kilobytes and Megabytes,
Gigabytes and Terabytes.
BIT - Binary digit i.e. 0 and 1
Byte - A string of fixed no. of bits is one Byte but in general 8
Bits form one Byte.
1024 Bytes - 1 Kilo byte (KB)
1024 KB - 1 Mega byte (MB)
1024 MB - 1 Giga byte (GB)
1024 GB - 1 Tera byte (TB)
ACCURACY
The amount of research that has gone into developing the computer to function
Optimally has created a device that operates at near 100% level of accuracy. Almost all
the errors that arise while it is operational, are a result of illogical programming
or incorrect provision of data or information. A very small percentage of its errors are
due to component malfunctions, which again may arise due to misuse and improper
handling of the equipment.
AUTOMATIC
As stated earlier, the computer is quite capable of functioning automatically, once
the process has been initiated. It does not require a prompt from an operator at each
stage of the process. Like a calculator it does not require a user
continuously/interactively. Rather the computer chip has made many-2 other devices as
automatic.
DILIGENCE
Man suffers from physical and mental fatigue, lack of concentration and laziness which
do not permit him to carry on his task at the same level of speed and accuracy through
the entire day. The computer, on the other hand, is capable of operating at exactly the

3. same level of speed and accuracy even if it has to carry out the most voluminous
and complex operations for a long period of time.
SCIENTIFIC APPROACH
The entire approach to solving problems is highly scientific, objective and
sequentially carried out, leaving no room for emotional and subjective evaluations made
by man, which are sources of potential errors and unjustified results.
VERSATILITY
The wide use of computers in so many areas of man’s daily life is ample evidence
of its versatility. It can carry out processes ranging from simple
mathematical calculations to highly complex and logical evaluations.
LOGICAL DECISIONS
Apart from computation a computer has a capability to take decisions, which imparts it
some intelligence. These decisions called Logical Decisions depend upon
certain conditions. By a logical decision we mean that computer is capable of deciding
the path it is to choose, out of various alternatives available to it. For example, a
computer can execute instructions such as, if a purchase is worth Rs. 2000 or above
allow a discount in the bill of 15%, otherwise a discount of 10%. In this case, the
computer has two alternatives and in order to select the correct alternative, it
compares the purchase bill amount with Rs. 2000 and depending upon the result it
computes a discount of 15% or 10%.
In short, a computer is capable of comparing data and depending upon the results of this
comparison, it can take appropriate actions. It must be borne in mind that data
to be compared need not necessarily be numerical, a computer can handle non-
numerical data also.
CONNECTIVITY AND NETWORKING
The computers can be connected with each other and
processing of data/information on a centralized computer through terminals is
possible. Using the concept of networking we can contact with the computers
located away at very long distances. In other words we can share information’s and
resources at distances ranging from a few hundred meters to as far as overseas, if the
systems are connected through networks.
LIMITATIONS OF A COMPUTER
Besides so many characteristics or capabilities of computers, here are listed below
some limitations of computers.
i) Doesn’t have much intelligence or I.Q. and judgment.
ii) Heavily dependent on human beings.
iii) Need for special languages to perform. Time taken in planning, designing of system
and writing of programs.
iv) Needs controlled environments.
v) Needs overall efficiency of all human beings involved in the system.
vi) Strict quality control for cards, floppies, tapes, papers etc. is required.
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