•It refers to the physical components that make
up a computer system.
•There are many different kinds of hardware that
can be installed inside, and connected to the outside, of a computer.
•In information technology, hardware is the
physical aspect of computers, telecommunications, and other devices.
•Hardware includes not only the computer but also
the cables, connectors, power supply units, and peripheral devices such as the
keyboard, mouse, audio speakers, and printers.
BLOCK DIAGRAM OF COMPUTER
•A computer is a programmable machine designed to
sequentially and automatically carry out a sequence of arithmetic or logical
operations. The particular sequence of operations can be changed allowing the
computer to solve more than one kind of problem.
•Basic Structure: The basic components of a
ØMemory /Storage Unit
ØArithmetic Logic Unit
ØCentral Processing Unit
Following Functions are performed by an Input unit:
accepts the instruction and data from the outside world.
converts these instructions and data in computer acceptable form.
supplies the converted instructions and data to the computer system for further
•Central Processing Unit: The main unit
inside the computer is the CPU. This unit is responsible for all events inside
•Also called Microprocessor or just Processor
•It controls all internal and external devices,
performs arithmetic and logic operations.
•CPU is the brain of the system.
The processor logically consists of the following units:
•B)Arithmetic Logic Unit (ALU)
•The control unit maintains order within the
computer system and directs the flow of traffic (operations) and data.
•The flow of control is indicated by the dotted
•The control unit selects one program statement
at a time from the program storage area, interprets the statement, and sends
the appropriate electronic signals to the arithmetic-logic unit and storage
section to cause them to carry out the instruction.
•The arithmetic-logic unit (ALU) performs all
arithmetic operations (addition, subtraction, multiplication, and division) and
•Logic operations tests various conditions
encountered during processing and allows for different actions to be taken
based on the results.
•The data required to perform the arithmetic and
logical functions are inputs from the designated CPU registers and operands.
•The ALU relies on basic items to perform its
•These include number systems, data routing
circuits (adders/subtracter), timing, instructions, operands, and registers.
•CPU Registers are a group of circuits used for
memory addressing, data operation and processing.
•Examples – Accumulator register, Program Counter
register, Instruction register
Computer in Hiding
•In our day to day life we experience many things
carried in automated ways but these are operations carried by computers behind
•For example when we debit or credit from ATM
machine, behind the scene there are many computers, applications and concept
like networking which plays major role.
•Large Computers indicates here the mega systems
which perform the tasks at backend like reservation systems, internet etc.
•Thus many of our daily activities, such as
making reservations. Watching weather forecast, or withdrawing money from ATM
machine are actually interactions with computer system that you don’t see.
•Small Computers: indicates small automated
machines or networks which work at back end and facilitates the end user.
•Here microcontrollers are used in automatically
controlled products and devices, such as automobile engine control systems,
implantable medical devices, remote controls, office machines appliances. power
tools, toys and other embedded systems.
•Embedded computers can be compared to
"computers on a chip".
•It may be clear that these devices are mostly
used for controlling.
•A system on a chip or system on chip (SoC) is an
integrated circuit (IC) that integrates all components of a computer system
into a single chip.
•It may contain digital, analog, mixed-signal,
and often radio-frequency functions-all on a smallcomputer on a single chip substrate.
•A microcontroller (sometimes abbreviated uC or
MCU) is a small computer on a single integrated circuit containing a processor
core, memory, and programmable input/output peripherals.
•Microcontrollers are designed for embedded
applications, in contrast to the microprocessors used in personalcomputers other general purpose applications
Applications of IT
I.T in business: Most business activities involve
transactions with suppliers, employees, or customers These transactions are
possible using information processing system.
Using desktop publishing programs, or even sophisticated
word processing programs, people can create sales letters, brochures, price
lists, newsletters, and even hook-length manuals.
IT has made it
possible for business to be open 24 x7 all over the globe. This means that a
business can be open anytime anywhere, making purchases from different
countries easier and more convenient.
I.T in industry: Information technology has major
impact in industries where products are designed and manufactured Computer
aided design (CAD) is used to design the products and computer aided
manufacturing is used to produce them
Product design: Computer-Aided Design programs
reduced the need of draftsmen significantly especially in small to mid-sized
CAD is used in the design of tools and machinery and in the
drafting and design of all types of buildings, from small residential types
(houses) to the largest commercial and industrial structures (hospitals and
CAD is an important industrial art extensively used in many
applications, including automotive, shipbuilding, and aerospace industries,
industrial and architectural design.
Product manufacturing Computer-aided manufacturing (CAM) is
the use of computer software to control machine tools and related machinery in
the manufacturing of work pieces.
CAM may also refer to
the use of a computer to assist in all operations of a manufacturing plant,
including planning management, transportation and storage.
I.T at home and play: From the comfort of your home
you can research school or work assignments, exchange e-mail, join special
interest groups, download files, play games, or make railway and airline
reservations from any computer with an internet connection.
You can read the newspaper, shop online, or read reviews of
the movie. Home shopping and banking are growing areas of computing
I.T in education and training: Information Technology
plays a key role in the modern systems of education.
Students find it easier to refer to the Internet than
searching for information in books. The process of learning has gone beyond
learning from prescribed textbooks.
Online education has revolutionized the education industry
The Information technology has made dream of distance learning, a reality.
Education is no more limited to classrooms. It has reached
far and wide thanks to the computer technology physically distant locations
have come close to each other only due to computer networking.
Information technology facilitates an efficient storage and
effective presentation of information Presentation software like PowerPoint and
animation software like Flash and others can be of great help to the teachers
while delivering information.
Computers can turn out being a brilliant aid in
teaching. Computers facilitate an audio-visual representation of information,
thus making the process of learning interactive and interesting. Computer-aided
teaching adds a fun element to education
Internet can play an important role in education. As it is
an enormous information base, it can be used for the retrieval of information
on a wide variety of subjects. The Internet can be used to refer to information
on various subjects to be taught to the students. CBT:-Computer-Based Training,
a type of education in which the student learns by executing special training
programs on a computer.
I.T in science and engineering: Information technology
plays a major role today in every field of scientific research from genetic
engineering to astrophysics research. One of the prime uses of information
technology in pure science and engineering projects is the running of
simulations. Physicians use information technology to understand the human body
and to diagnose disorders