BLOCK DIAGRAM
OF COMPUTER
SYSTEM
Computer system
consists of three parts,
that are central
processing unit
(CPU), Input Devices,
and Output Devices. The
Central Processing Unit
(CPU) is divided into two
parts again: arithmetic
logic unit (ALU) and the
control unit (CU). The set
of instruction is in the
form of raw data.
A LARGE AMOUNT OF DATA IS STORED IN THE COMPUTER MEMORY WITH
THE HELP OF PRIMARY AND SECONDARY STORAGE DEVICES. THE CPU IS LIKE
THE HEART/BRAIN OF THE COMPUTER. THE USER DOES NOT GET THE
DESIRED OUTPUT, WITHOUT THE NECESSARY OPTION TAKEN BY THE
CPU. THE CENTRAL PROCESSING UNIT (CPU) IS RESPONSIBLE FOR THE
PROCESSING OF ALL THE INSTRUCTIONS WHICH ARE GIVEN BY THE USER TO
THE COMPUTER SYSTEM.
THE DATA IS ENTERED THROUGH INPUT DEVICES SUCH AS THE KEYBOARD,
MOUSE, ETC. THIS SET OF INSTRUCTION IS PROCESSED BY THE CPU AFTER
GETTING THE INPUT BY THE USER, AND THEN THE COMPUTER SYSTEM
PRODUCES THE OUTPUT. THE COMPUTER CAN SHOW THE OUTPUT WITH
THE HELP OF OUTPUT DEVICES TO THE USER, SUCH AS MONITOR, PRINTER,
ETC.
Input Devices
• The user provides the set of
instruction or information to the
computer system with the help of
input devices such as the keyboard,
mouse, scanner, etc. The data
representation to the computer
system is in the form of binary
language after that the processor
processes the converted data. The
input unit implements the data
which is instructed by the user to
the system.
• We can enter the data from the
outside world into the primary
storage as the input through input
devices. The input devices are the
Central Processing Unit (CPU)
• The computer system is nothing without the Central processing Unit so, it is also known as the
brain or heat of computer. The CPU is an electronic hardware device which can perform
different types of operations such as arithmetic and logical operation.
The CPU contains two parts: the arithmetic logic unit and control unit.
Control Unit
• The control unit (CU) controls all the activities or operations which are performed inside the
computer system. It receives instructions or information directly from the main memory of the
computer.
• When the control unit receives an instruction set or information, it converts the instruction set
to control signals then; these signals are sent to the central processor for further processing.
The control unit understands which operation to execute, accurately, and in which order.
Arithmetic and Logical Unit
• The arithmetic and logical unit is the combinational digital electronic circuit that can perform
arithmetic operations on integer binary numbers. It presents the arithmetic and logical
operation. The outputs of ALU will change asynchronously in response to the input. The basic
arithmetic and bitwise logic functions are supported by ALU.
Storage Unit
• The information or set of guidelines are stored in the storage unit of the computer system. The storage unit
provides the space to store the data or instruction of processed data. The information or data is saved or
hold in computer memory or storage device. The data storage is the core function and fundamental of the
computer components.
Primary Memory
• The inbuilt memory of the computer is called primary memory.
• The Random Access Memory is the main memory of the computer system, which is known as RAM. The
main memory can store the operating system software, application software, and other information. The
Ram is one of the fastest memory, and it allows the data to be readable and writeable.
• ROM stands for Read Only Memory. They contain data that does not need to be altered, like booting
sequence of a computer or algorithmic tables for mathematical applications. It retains its data even when
power is switched off, i.e. it is non-volatile.
Secondary memory
• We can store the data and programs on a long-term basis in the secondary memory. The hard disks and the
optical disks are the common secondary devices. It is slow and cheap memory as compare to primary
memory. This memory is not connected to the processor directly.
• It has a large capacity to store the data. The hard disk has a capacity of 500 gigabytes. The data and
programs on the hard disk are organized into files, and the file is the collection of data on the disk. The
secondary storage is direct access by the CPU; that’s why it is different from the primary storage.
Output Devices
• The output devices produce or
generate the desired result
according to our input, such as a
printer, monitor, etc. These devices
convert the data into a human-
readable form from binary code.
• The computer system is linked or
connected to the outside world
with the help of output devices.
The primary examples of output
devices are a printer, projector, etc.
APPLICATIONS OF COMPUTERS IN VARIOUS
FIELDS
Uses Of Computer At Home
• Budget
Computer can be used to manage Home Budget. You can easily calculate your
expenses and income. You can list all expenses in one column and income in
another column. Then you can apply any calculation on these columns to plan
your home budget. There are also specialize software that can manage your
income and expenses and generate some cool reports.
• Computer Games
An important use of computers at home is playing games. Different types of
games are available. These games are a source of entertainment and
recreation. Many games are available that are specially developed to improve
your mental capability and thinking power.
• Working From Home
People can manage the office work at home. The owner of a company can
• Entertainment
People can find entertainment on the internet. They can watch movies,
listen to songs, and watch videos download different stuff. They can
also watch live matches on the internet.
• Information
People can find any type of information on the internet. Educational
and informative websites are available to download books, tutorials
etc. to improve their knowledge and learn new things.
• Chatting & Social Media
People can chat with friends and family on the internet using different
software like Skype etc. One can interact with friends over social media
websites like Facebook, Twitter & Google Plus. They can also share
photos and videos with friends.
USES OF COMPUTERS IN EDUCATION
• Computer Aided Learning (CAL)
Computer aided learning is the process of using information technology to
help teaching and enhance the learning process. The use of computer can
reduce the time that is spent on preparing teaching material. It can also
reduce the administrative load of teaching and research. The use of
multimedia projector and PowerPoint presentations has improved the quality
of teaching. It has also helped the learning process.
• Distance Learning
Distance learning is a new learning methodology. Computer plays the key role
in this kind of learning. Many institutes are providing distance learning
programs. The student does not need to come to the institute. The institute
provides the reading material and the student attends virtual classroom. In
virtual classroom, the teacher delivers lecture at his own workplace. The
student can attend the lecture at home by connecting to a network. The
• Online Examination
The trend of online examination is becoming popular. Different
examination like GRE, GMAT and SAT are conducted online all
over the world. The questions are marked by computer. It
minimizes the chance of mistakes. It also enables to announce
the result in time
USES OF COMPUTERS IN BUSINESS
• Marketing
An organization can use computers for marketing their products.
Marketing applications provide information about the products to
customers. Computer is also used to manage distribution system,
advertising and selling activities. It can also be used in deciding pricing
strategies. Companies can know more about their customers and their
needs and requirements etc.
• Stock Exchange
Stock Exchange is the most important place for businessmen. Many
stock exchanges use computers to conduct bids. The stockbrokers
perform all trading activities electronically. They connect with the
computer where brokers match the buyers with sellers. It reduces cost
as no paper or special building is required to conduct these activities.
USES OF COMPUTERS IN MEDICAL FIELD
• Hospital Management System
• Specialized hospital management softwares are used to
automate the day to day procedures and operations at
hospitals. These tasks may be Online appointments, payroll
admittance and discharge records etc.
• Patient History
• Hospital management systems can store data about patients.
Computers are used to store data about patients, their diseases
& symptoms, the medicines that are prescribed.
• Patients Monitoring
Monitoring systems are installed in medical wards and Intensive
care units to monitoring patients continously. These systems can
monitor pulse, blood pressure and body temperature and can
alert medical staff about any serious situations.
• Life Support Systems
Specialised devices are used to help impaired patients like
hearing aids.
• Diagnosis Purpose
A variety of softwares are used to investigate symptoms and
prescribed medication accordingly. Sophisticated systems are
used for tests like CT Scan, ECG, and other medical tests.