The documents above contains summarized notes on computer Application and Computer System which will give you a better understanding on computers. As a computer science or an I.T student, take these notes seriously.
COMPUTER APPLICATION
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 −
,A TOPIC OF COMPUTER SCIENCE
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
, A TOPIC OF COMPUTER SCIENCE
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.
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller kentigercorp. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $8.29. You're not tied to anything after your purchase.
