Basics of computers.pptx

Basics of computers
• A computer is an electronic device, operating under
the control of instructions stored in its own memory
that can accept data (input), process the data
according to specified rules, produce information
(output), and store the information for future use1.
• Functionalities of a computer
• Any digital computer carries out five functions in
gross terms:

Computer Components
• Any kind of computers consists of HARDWARE AND
SOFTWARE.
• Hardware:
• Computer hardware is the collection of physical
elements that constitutes a computer system.
Computer hardware refers to the physical parts or
components of a computer such as the monitor,
mouse, keyboard, computer data storage, hard drive
disk (HDD), system unit (graphic cards, sound cards,
memory, motherboard and chips), etc. all of which are
physical objects that can be touched.3

Input Devices
• Input device is any peripheral (piece of computer hardware
equipment to provide data and control signals to an
information processing system such as a computer or other
information appliance.

Cont….
• Input device Translate data from form that
humans understand to one that the computer
can work with. Most common are keyboard
and mouse

1. Keyboard 2. Mouse (pointing
device) 3. Microphone
4. Touch screen 5. Scanner 6. Webcam
7. Touchpads 8. MIDI keyboard 9.
10.Graphics Tablets 11.Cameras 12.Pen Input
13.Video Capture Hardware 14.Microphone 15.Trackballs
16.Barcode reader 17.Digital camera 18.Joystick
19.Gamepad 20.Electronic Whiteboard 21.

Central Processing Unit (CPU)
• A CPU is brain of a computer. It is responsible for
all functions and processes. Regarding computing
power, the CPU is the most important element of
a computer system.
• The CPU is comprised of three main parts :
• Arithmetic Logic Unit (ALU): Executes all
arithmetic and logical operations. Arithmetic
calculations like as addition, subtraction,
multiplication and division. Logical operation like
compare numbers, letters, or special characters

Cont….
• Control Unit (CU): controls and co-ordinates computer
components.
– Read the code for the next instruction to be executed.
– Increment the program counter so it points to the next
instruction.
– Read whatever data the instruction requires from cells in
memory.
– Provide the necessary data to an ALU or register.
– If the instruction requires an ALU or specialized hardware
to complete, instruct the hardware to perform the
requested operation.
• * Registers :Stores the data that is to be executed next,
"very fast storage area".

Primary Memory:-
• RAM: Random Access Memory (RAM) is a memory
scheme within the computer system responsible for
storing data on a temporary basis, so that it can be
promptly accessed by the processor as and when
needed. It is volatile in nature, which means that data
will be erased once supply to the storage device is
turned off. RAM stores data randomly and the
processor accesses these data randomly from the RAM
storage. RAM is considered "random access" because
you can access any memory cell directly if you know
the row and column that intersect at that cell.

Cont….
• ROM (Read Only Memory): ROM is a
permanent form of storage. ROM stays active
regardless of whether power supply to it is
turned on or off. ROM devices do not allow
data stored on them to be modified.

Secondary Memory:-
• Stores data and programs permanently :its
retained after the power is turned off
• Hard drive (HD): A hard disk is part of a unit,
often called a "disk drive," "hard drive," or
"hard disk drive," that store and provides
relatively quick access to large amounts of
data on an electromagnetically charged
surface or set of surfaces.

• Optical Disk: an optical disc drive (ODD) is a
disk drive that uses laser light as part of the
process of reading or writing data to or from
optical discs. Some drives can only read from
discs, but recent drives are commonly both
readers and recorders, also called burners or
writers.

Cont….
• Compact discs, DVDs, and Blu-ray discs are common
types of optical media which can be read and recorded
by such drives. Optical drive is the generic name; drives
are usually described as "CD" "DVD", or "Bluray",
followed by "drive", "writer", etc. There are three main
types of optical media: CD, DVD, and Blu-ray disc. CDs
can store up to 700 megabytes (MB) of data and DVDs
can store up to 8.4 GB of data. Blu-ray discs, which are
the newest type of optical media, can store up to 50
GB of data. This storage capacity is a clear advantage
over the floppy disk storage media (a magnetic media),
which only has a capacity of 1.44 MB.

Cont….
• Flash Disk
• A storage module made of flash memory
chips. A Flash disks have no mechanical
platters or access arms, but the term "disk" is
used because the data are accessed as if they
were on a hard drive. The disk storage
structure is emulated.

Output devices
• An output device is any piece of computer
hardware equipment used to communicate
the results of data processing carried out by
an information processing system (such as a
computer) which converts the electronically
generated information into human- readable
form.

Example on Output Devices
1. Monitor 2. LCD Projection Panels
3. Printers (all types) 4. Computer Output Microfilm (COM)
5. Plotters 6. Speaker(s)
7. Projector
:
Note Basic types of monitors are a.Cathode Ray
Tube (CRT). B. Liquid Crystal Displays (LCD). c.light-
emitting diode (LED).
Printer types: 1-Laser Printer. 2-Ink Jet Printer. 3-
Dot Matrix Printer

Software
• Software is a generic term for organized
collections of computer data and instructions,
often broken into two major categories:
system software that provides the basic non-
task-specific functions of the computer, and
application software which is used by users to
accomplish specific tasks.

Cont….
• Software Types
• System software is responsible for controlling,
integrating, and managing the individual hardware
components of a computer system so that other
software and the users of the system see it as a
functional unit without having to be concerned with
the low-level details such as transferring data from
memory to disk, or rendering text onto a display.
Generally, system software consists of an operating
system and some fundamental utilities such as disk
formatters, file managers, display managers, text
editors, user authentication (login) and management
tools, and networking and device control software.

Cont….
• Application software is used to accomplish specific tasks
other than just running the computer system. Application
software may consist of a single program, such as an image
viewer; a small collection of programs (often called a
software package) that work closely together to accomplish
a task, such as a spreadsheet or text processing system; a
larger collection (often called a software suite) of related
but independent programs and packages that have a
common user interface or shared data format, such as
Microsoft Office, which consists of closely integrated word
processor, spreadsheet, database, etc.; or a software
system, such as a database management system, which is a
collection of fundamental programs that may provide some
service to a variety of other independent applications.

Comparison Application Software and System Software
System Software Application Software
Computer software, or just
software is a general term
primarily used for digitally
storeddata such as computer
programs and other kinds of
information read and written by
computers. App comes under
computer software though it has
a wide scope now.
Application software, also
known as an application or an
"app", is computer software
designed to help the user to
perform specific tasks.
Example:
1) Microsoft Windows
2) Linux
3) Unix
4) Mac OSX
5) DOS
1) Opera (Web Browser)
2) Microsoft Word (Word
Processing)
3) Microsoft Excel (Spreadsheet
software)
4) MySQL (Database Software)
5) Microsoft PowerPoint
(Presentation Software)
6) Adobe Photoshop (Graphics
Software)
Interaction
:
Generally, users do not interact
with systemsoftware as it works
in the background.
Users always interact with
application softwarewhile doing
different activities.
Dependenc
y:
System software can run
independently of the
application software.
Application software cannot run
without the
presence of the system software.

Cont….
• Unit of Measurements
• Storage measurements: The basic unit used in
computer data storage is called a bit (binary digit).
Computers use these little bits, which are composed of
ones and zeros, to do things and talk to other
computers. All your files, for instance, are kept in the
computer as binary files and translated into words and
pictures by the software (which is also ones and zeros).
This two number system, is called a “binary number
system” since it has only two numbers in it. The
decimal number system in contrast has ten unique
digits, zero through nine.

Computer Storage units
Bit BIT 0 or 1
Kilobyte KB 1024 bytes
Megabyte MB 1024 kilobytes
Gigabyte GB 1024 megabytes
Terabyte TB 1024 gigabytes

Cont….
• Speed measurement: The speed of Central
Processing Unit (CPU) is measured by Hertz
(Hz), Which represent a CPU cycle. The speed
of CPU is known as Computer Speed.

CPU SPEED MEASURES
1 hertz or Hz 1 cycle per second
1 MHz 1 million cycles per second or 1000 Hz
1 GHz 1 billion cycles per second or 1000 MHz

Computers classification***
• Computers can be generally classified by size and
power as follows, though there is Considerable
overlap:
• Personal computer: A small, single-user computer
based on a microprocessor. In addition to the
microprocessor, a personal computer has a keyboard
for entering data, a monitor for displaying information,
and a storage device for saving data.
• workstation : A powerful, single-user computer. A
workstation is like a personal computer, but it has a
more powerful microprocessor and a higher-quality
monitor.

Cont….
• minicomputer : A multi-user computer
capable of supporting from 10 to hundreds of
users simultaneously.
• mainframe : A powerful multi-user computer
capable of supporting many hundreds or
thousands of users simultaneously.
• supercomputer : An extremely fast computer
that can perform hundreds of millions of
instructions per second.

Laptop and Smartphone Computers
• LAPTOP: A laptop is a battery or AC-powered
personal computer that can be easily carried and
used in a variety of locations. Many laptops are
designed to have all of the functionality of a
desktop computer, which means they can
generally run the same software and open the
same types of files.
• However, some laptops, such as netbooks,
sacrifice some functionality in order to be even
more portable.

Cont….
• Netbook: A netbook is a type of laptop that is
designed to be even more portable. Netbooks
are often cheaper than laptops or desktops.
• They are generally less powerful than other
types of computers, but they provide enough
power for email and internet access, which is
where the name "netbook" comes from.

• Mobile Device: A mobile device is basically any
handheld computer. It is designed to be
extremely portable, often fitting in the palm of
your hand or in your pocket. Some mobile
devices are more powerful, and they allow you to
do many of
the same things you can do with a desktop or
laptop computer. These include tablet computers,
e-readers, and smartphones.
•

Cont….
• Smartphones: A smartphone is a powerful
mobile phone that is designed to run a variety
of applications in addition to phone service.
They are basically small tablet computers, and
they can be used for web browsing, watching
videos, reading e-books, playing games and
more.

Data, Information and Knowledge
• Data: Facts and figures which relay something
specific, but which are not organized in any
way and which provide no further information
regarding patterns, context, etc.
• So data means "unstructured facts and figures
that have the least impact on the typical
manager."

Cont….
• Information: For data to become information, it
must be contextualized, categorized, calculated
and condensed.
• Information thus paints a bigger picture; it is data
with relevance and purpose.
• It may convey a trend in the environment, or
perhaps indicate a pattern of sales for a given
period of time.
• Essentially information is found "in answers to
questions that begin with such words as who,
what, where, when, and how many".

Cont….
• Knowledge: Knowledge is closely linked to
doing and implies know-how and
understanding.
• The knowledge possessed by each individual is
a product of his experience, and encompasses
the norms by which he evaluates new inputs
from his surroundings.

Cont….
• The content of the human mind can be classified into
four categories:
• Data: symbols
• Information: data that are processed to be useful;
provides answers to "who", "what", "where", and
"when" questions
• Knowledge: application of data and information;
answers "how" questions
• Wisdom: evaluated understanding.
• We need to understand that processing data produced
Information and process Information produces
Knowledge and so on

Characteristics of Computer
• Speed, accuracy, diligence, storage capability
and versatility are some of the key
characteristics of a computer. A brief overview
of these characteristics are

Cont….
• Speed: The computer can process data very fast,
at the rate of millions of instructions per second.
Some calculations that would have taken hours
and days to complete otherwise, can be
completed in a few seconds using the computer.
For example, calculation and generation of salary
slips of thousands of employees of an
organization, weather forecasting that requires
analysis of a large amount of data related to
temperature, pressure and humidity of various
places, etc.

Cont….
• Accuracy: Computer provides a high degree of
accuracy. For example, the computer can
accurately give the result of division of any
two numbers up to 10 decimal places.
• Diligence: When used for a longer period of
time, the computer does not get tired or
fatigued. It can perform long and complex
calculations with the same speed and
accuracy from the start till the end

Cont….
• Storage Capability: Large volumes of data and
information can be stored in the computer
and also retrieved whenever required.
• A limited amount of data can be stored,
temporarily, in the primary memory.
Secondary storage devices like floppy disk and
compact disk can store a large amount of data
permanently.

Cont….
• Versatility: Computer is versatile in nature. It can
perform different types of tasks with the same
ease.
• At one moment you can use the computer to
prepare a letter document and in the next
moment you may play music or print a
document.
• Computers have several limitations too.
Computer can only perform tasks that it has been
programmed to do.

Cont….
• Computer cannot do any work without
instructions from the user.
• It executes instructions as specified by the
user and does not take its own decisions.

Computer Viruses*
• Viruses: A virus is a small piece of software
that piggybacks on real programs.
• For example, a virus might attach itself to a
program such as a spreadsheet program.
• Each time the spreadsheet program runs, the
virus runs, too, and it has the chance to
reproduce (by attaching to other programs) or
wreak havoc.

Cont….
• E-mail viruses: An e-mail virus travels as an
attachment to e-mail messages, and usually
replicates itself by automatically mailing itself
to dozens of people in the victim's e-mail
address book.
• Some e-mail viruses don't even require a
double-click -- they launch when you view the
infected message in the preview pane of your
e-mail software [source: Johnson].

Cont….
• Trojan horses: A Trojan horse is simply a computer
program. The program claims to do one thing (it may
claim to be a game) but instead does damage when
you run it (it may erase your hard disk). Trojan horses
have no way to replicate automatically.
• •Worms: A worm is a small piece of software that uses
computer networks and security holes to replicate
itself. A copy of the worm scans the network for
another machine that has a specific security hole. It
copies itself to the new machine using the security
hole, and then starts replicating from there, as well.

Basics of computers.pptx

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Basics of computers.pptx