UNIT 1
Unit 1: Basics of Information Technology
Familiarity with the basics of computers: design of computers, and overview of communication technologies Computer Systems: characteristics of a computer, components of a computer system – CPU, memory, storage devices and I/O devices
Memory: primary (RAM and ROM) and secondary memory
Storage devices: hard disk, CD ROM, DVD, pen/flash drive, memory stick
I/O devices: keyboard, mouse, monitor, printer, scanner, web camera click here to download input output devices
Types of software: system software (operating systems), application software, mobile applications
Operating systems: kernel, device drivers, and file systems (very basic idea)
Computer networking: wired/wireless communication, common protocols: Wi-Fi, Bluetooth, cloud computers (private/public)
Multimedia: images, audio, video, animation
Chat sites, and social networks
INPUT OUTPUT DEVICES
INTRODUCTION TO WINDOW 7
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There
are two types of CDs: CD-R and
CD-RW.
CD-RW
stands for Compact Disk – ReWriteable which can read, write and erase data as
many times.
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BASICS OF INFORMATION TECHNOLOGY
Familiarity with the basics of computers:
·
Design of computers
Computer System is
a group of interconnected components that work together in an integrated manner
to perform a particular task.
·
Communications technology, also
known as information technology, refers to all equipment and
programs that are used to process and communicate information.
Professionals in the communication technology field specialize
in the development, installation, and service of these hardware and software
systems.
Different types of communication technology
·
mail. You must answer
your email or hire someone to do it for you. ...
·
Texting. Texting has
become the most personal form of business communication. ...
·
Instant Messaging. ...
·
Social Networking. ...
·
Tweeting. ...
·
Blogs. ...
·
Video Conferencing.
Computer
Systems:
Characteristics of computer
Speed: Computers can work at incredible speed.
• Accuracy: Computers are extremely accurate.
• Huge Memory: Computers can store and retrieve huge
amount of data.
• Diligence: Unlike humans a computer has the
ability to work for a long time without getting tired.
• Versatile: A computer can perform different
types of operations.
• No Feelings: Unlike humans computer do not have
any feelings.
Components of Computer system
CPU
The central processing unit (CPU) is the
brain of your computer. It handles all the instructions you give your computer.
CPU (pronounced as separate letters) is the
abbreviation for central processing unit. Sometimes referred to simply as the
central processor, but more commonly called processor,
the CPU is the brains of the computer where
most calculations take place.
Memory
Memory is where data and
instructions are held.
The different
types of memories that forms the Memory Unit of the Computer System are:
• CPU Registers
• Cache Memory
• Main Memory
• Secondary Memory
Memory, storage, files and folder
sizes are all measured in bytes. Computers work in the base 2 system, also
called binary number system, using only the digits 0 and 1. A single numeric
value using either 0 or 1 is called a bit.
A sequence of ‘bits’ make a byte.
Usually eight bits make a byte (sometimes it could be sixteen, thirty two or
even sixty four). Bits are grouped into bytes to increase the efficiency of the
computer. To describe large capacities, the terms Kilobyte (KB), megabyte (MB),
gigabyte (GB), terabyte (TB) and Petabyte (PB) are used.
Storage Devices
Storage devices are
the devices which are used to retrieved from and saved to the data and information such as hard drives,
memory sticks (pen drives), compact discs, DVDs and tape drives.
1. 
Floppy disks were
developed in late 1960s. A floppy disk is made up of a circular thin plastic jacket coated with magnetic material.
Its outer cover which is a hard plastic protects this plastic disk. It can hold
1.44 MB data. Nowadays, these disks are outdated.
Floppy disks were
developed in late 1960s. A floppy disk is made up of a circular thin plastic jacket coated with magnetic material.
Its outer cover which is a hard plastic protects this plastic disk. It can hold
1.44 MB data. Nowadays, these disks are outdated.
2. 
Hard Disk is
made up of a metal disk and coated with a
metal oxide used to store bulk of data. These disks can store more
information than floppy disks, up to tens or hundreds of gigabytes.
Hard Disk is
made up of a metal disk and coated with a
metal oxide used to store bulk of data. These disks can store more
information than floppy disks, up to tens or hundreds of gigabytes.
3. Compact Disk –
Read Only Memory or CD-ROM is a read only or
read-write disk. It can store large
amount of data which can be distributed to large number of users. It is
inexpensive and fast, but its access time is longer than that of magnetic disk.
There
are two types of CDs: CD-R and
CD-RW.
CD-R stands for Compact Disk – Recordable which can store
700 MB of data, but only once.
CD-RW
stands for Compact Disk – ReWriteable which can read, write and erase data as
many times.
4. DVD, short for Digital Versatile Disc, is an optical storage disc
similar to CD-ROM, as this is double
sided with dual layer disc and can hold 4.7 GB of data.
5. Blue-Ray Disks are used to store more than 25 GB of data with a very high
speed in less amount of time. A
single layer of BD can store 13 hours of video where as double layer BD can
store more than 20 hours of video.
6. USB stands for Universal Serial Bus. It is a portable memory
device which is used to store data
that needs to be transferred to the other device using USB port of the system.
7. Memory Card or flash memory card is a memory device. It is used as an easy, fast and reliable medium to
store and transfer data from one device to the other. It is used in digital
cameras, game consoles, mobile phones etc.
I/O Devices
Input devices are
components of a computer system through which data is given to the computer for
processing. Example- Keyboard and Mouse.
Output devices are used to display the result or information
to the user through monitor or VDUs, LCDs, printers, plotters and speakers.
Functions
of output devices
❖ It accepts the results produced by the computer which is in
the coded form or machine readable form.
❖ It converts these coded results into human readable form. ❖ It supplies the converted results to the user.
Memory
Computer memory is
any physical device capable of storing information temporarily or permanently
Primary
primary storage (main
storage or primary memory) 1) Primary storage,
also known as main storage ormemory, is the area in
a computer in which data is stored for quick access by
the computer's processor. The terms random access memory (RAM)
andmemory are often as synonyms for primary or main
storage
(RAM/
ROM)
The memory unit of CPU is further divided
into two components, one is known as
Random Access Memory (RAM) to take care of intermediate storage
of data while
working on a computer system and another.
Read Only Memory (ROM) to keep the essential instructions written
and stored by the manufacturer to load operating
system and take care of basic input/output
operations – also referred as BIOS i.e.
Basic Input Output
System
Secondary
Secondary memory is
where programs and data are kept on a long-term basis. Common secondary storage
devices are the hard disk and optical disks. The hard disk has enormous storage
capacity compared to main memory. The hard disk is usually
contained inside the case of a computer.
I/O DEVICES
An input/output (I/O) device is
a hardware device that has the ability to accept inputted,
outputted or other processed data. It also can acquire respective media data as
input sent to a computer or send computer data to storage media as storage
output. An I/O device is also known as an IO device.
TYPES OF SOFTWARE:
Software
Software refers to a program or
group of instructions that are given to the computer, which is
stored in the main memory to perform
a specific job.
System Software.
Ans. System software is collection
of programs that is used to service or help other programs during
execution.
The different types of
System Software are:
• Operating System
• Utility Programs
• Library Programs
• Programming
Language Translators
Operating System:
An Operating System is a System Software
that manages and serves other programs and also
provides an interface for the user
to interact with a computer.
Q30. An application is any program, or group
of programs, that is designed for the end user.
Applications software(also called end-user
programs) include such things as database programs, word processors, Web
browsers and spreadsheets
·
Mobile application,
Most
commonly referred to as an app, is a type of application software designed to
run on a mobile device, such as a smartphone or tablet computer. Mobile
applications frequently serve to provide users with similar services to those
accessed on PCs. Apps are generally small, individual software units with
limited function. This use of app software was originally popularized by Apple
Inc. and its App Store, which offers thousands of applications for the iPhone,
iPad and iPod Touch.
A
mobile application also may be known as an app, web app, online app, iPhone app
or smartphone app.
·
Kernal
The 'kernel' is
the central component of most computer operating systems; it is a
bridge between applications and the actual data processing done at the hardware
level. The kernel's responsibilities include managing the
system's resources (the communication between hardware and software components)
·
Device driver
Program that controls
a particular type of device that is attached to your computer.
There are device drivers for printers, displays, CD-ROM readers,
diskette drives, and so on. When you buy an operating system, many device
drivers are built into the product.
·
File system
Alternatively referred to
as file management and sometimes abbreviated as FS, a file
system is a method of organizing and retrieving files from a storage
medium, such as a hard drive. ... Directories can contain files or additional
directories. Today, the most commonly used file system with
Windows is NTFS.
Computer Networking:
Connects computers, mobile
phones, peripherals, and even IoT devices. Switches, routers, and wireless
access points are the essential networking basics. Through them,
devices connected to your network can communicate with one
another and with other networks, like the Internet wired/wireless communication
Wired communication
Refers to the transmission of data over a wire-based
communication technology. Examples include telephone networks,
cable television or internet access, and fiber-optic communication.
Wireless communication, or sometimes simply wireless,
is the transfer of information or power between two or more points that are not
connected by an electrical conductor. The most common wireless
technologies use radio waves.
·
Protocol
A protocol is a set of rules that governs the
communications between computers on a network.
·
Ethernet (Physical/Data Link Layers)
...
·
IP and IPX (Network Layer) ...
·
TCP and SPX (Transport Layer) ...
·
HTTP, FTP, SMTP and DNS
(Session/Presentation/Application Layers)
·
WiFi
WIFI is a short name for Wireless Fidelity".
Wi-Fi is
the name of a popular wireless networking technology that uses radio waves to
provide wireless high-speed Internet and network connections. A common
misconception is that the term Wi-Fi is short
for "wireless fidelity," however this is not the case. Wi-Fi is
simply a trademarked phrase that means IEEE 802.11x
·
Bluetooth
It is a wireless
technology standard for exchanging data over short distances (using
short-wavelength UHF radio waves in the ISM band from 2.4 to 2.485 GHz) from
fixed and mobile devices, and building personal area networks (PANs).
·
Cloud computing
It means storing
and accessing data and programs over the Internet instead of your computer's hard
drive. The cloud is just a metaphor for the Internet.
Public
Cloud. The main differentiator between public and private
clouds is that you aren't responsible for any of the management of
a public cloud hosting solution. Your data is stored in
the provider's data center and the provider is responsible for the
management and maintenance of the data center.
Multimedia:
Multimedia
means that computer information can be
represented through audio, video, and animation in addition to traditional
media (i.e., text, graphics drawings, images).
IMAGE
An image is a visual representation of
something. In information technology, the term has several usages: 1) An image is
a picture that has been created or copied and stored in electronic form.
An image can be described in terms of vector graphics or
raster graphics.
Audio
Audio is the sound system that comes
with or can be added to a computer. ... In order for users to receive sound in
real-time for a multimedia effect, listening to music, or in
order to take part in an audio or video conference, sound must
be delivered as streaming sound.
Video
Visual multimedia source that combines a
sequence of images to form a moving picture. The video transmits
a signal to a screen and processes the order in which the screen captures
should be shown. Videos usually have audio components that
correspond with the pictures being shown on the screen.
Animation
A simulation of movement created by
displaying a series of pictures, or frames. Cartoons on television is one
example of animation. Animation on computers is
one of the chief ingredients of multimedia presentations.
Chat:
Chat may
refer to any kind of communication over the Internet that
offers a real-time transmission of text messages from sender to receiver. Chat messages
are generally short in order to enable other participants to respond quickly.
·
There are three commonly
used types of chat.
They are Instant Messaging, ICQ,
and IRC. Instant messaging (IM) is one of
the most popular forms of chat. Most of the time, instant messaging (IM'ing)
is just between two people, although most IMsoftware can handle
group chats (with 3 or more people.)
·
Top 10 sites: chat and
instant messaging
·
www.aol.com/aim. ICQ. Now owned by AOL, ICQ (I
seek you, geddit?) ...
·
www.icq.com. MSN Messenger. ...
·
messenger.msn.com. TalkCity. ...
·
www.talkcity.com.
Internet Relay Chat. ...
·
www.irchelp.org.
Dobedo. ...
·
www.dobedo.co.uk. Habbo
Hotel. ...
·
www.habbohotel.com. Yahoo! ...
·
chat.yahoo.com. Virtual Zones.
·
SOCIAL NETWORKS:
A social network, in
technology parlance, is a website or other application where people, often of
similar interests, come together to communicate with each other.
·
Popular Social Media Sites
Facebook.- This
is easily the largest social networking site in the world
and one of the most widely used. ...
WhatsApp.- WhatsApp is a cross-platform instant messaging application
that allows iPhone, BlackBerry, Android, Windows Phone and Nokia smartphone
users to exchange text, image, video and audio messages for free.
QQ SOCIAL MEDIA-
WeChat.
QZone.
Tumblr.
Instagram.
Twitter.
Twitter is loved for spreading the
word via tweets. ...
LinkedIn.
Google +
YouTube.
Pinterest.
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Difference
Between Analog and Digital Computer
Analog Computer
|
Digital Computer
|
1.
The analogue computer works on a continuous
signal
|
The digital computer works on a discrete signal. This signal
has two states, on or off.
|
2.
The output is a voltage signal, they are not
exact values and are in graphical form.
|
The outputs are in numbers, exact values are seen on displays.
|
3.
These computers use a network of resistors
and capacitors.
|
Here a large number of logic gates, microprocessors and on-off
switches are used.
|
4.
Analogue computers have a limited ability to
act as a digital system.
|
The digital computers can emulate the behavior of analogue
computers.
|
5.
Analogue computers are slower in speed.
|
Digital computers are quite fast.
|
6.
These computers are mainly used in the field
of science.
|
These computers can be used in all fields of life.
|
7.
The analogue computers measure the analogue
quantities like voltage, temperature, etc.
|
The digital computers calculate mathematical operations,
complex calculations, media streaming, etc.
|
8.
Analogue computers are a bit difficult to
use.
|
Digital computers are quite easy to use.
|
9.
The data storing in analogue computers are
quite difficult as they use continuous signals which are difficult to store.
|
Storing data in digital computers are quite easy as they just
stores either 0 or 1 which can be easily stored.
|
Difference
Between RAM and ROM
BASIS FOR
COMPARISION
|
RAM
|
ROM
|
1.
Basic
|
It is a read-write memory.
|
It is read only memory.
|
2.
Use
|
Used to store the data that has to be currently processed by
CPU temporarily.
|
It stores the instructions required during bootstrap of the
computer.
|
3.
Volatility
|
It is a volatile memory.
|
It is a nonvolatile memory.
|
4.
Stands for
|
Random Access Memory.
|
Read Only Memory.
|
5.
Modification
|
Data in ROM can be modified.
|
Data in ROM can not be modified.
|
6.
Capacity
|
RAM sizes from 64 MB to 4GB.
|
ROM is comparatively smaller than RAM.
|
7.
Cost
|
RAM is a costlier memory.
|
ROM is comparatively cheaper than RAM.
|
8.
Type
|
Types of RAM are static RAM and dynamic RAM.
|
Types of ROM are PROM, EPROM, EEPROM.
|
Difference
Between Digital Camera and Web Camera
Digital Camera
|
Web Camera
|
1. They are Stand alone
Products
|
They are meant to be used for online Web Streaming
Purposes
|
2. They do not need any other
Product to support to function properly
|
They need support of a computer for proper
function.
|
3. Image quality is very good
|
Image
quality is usually poor
|
4. Also Work good in low
light
|
Don’t work
good in low light
|
5. They are expensive
|
They are
usually inexpensive
|
6. Digital Camera uses memory
card
|
It is
installed in Computer to store data
|
7. It is not connected to
Network
|
It is
directly connected to network
|
8. We cannot chat online
|
We can
chat directly online.
|
Differences
Between laser, Inkjet and DotMatrix Printer
Basis
|
Laser Printers
|
Inkjet
Printers
|
Dot
Matrix Printers
|
Invented
|
1969 by Gary Starkweather.
|
Developed in the early 1950s.
|
Introduced by Digital Equipment Corporation in 1970.
|
How it works
|
Laser printers use fine ink powder and heat the powder on the
paper.
|
Inkjet printers spray liquid ink on paper through microscopic
nozzles.
|
Dot Matrix works having pins pushed against an ink soaked ribbon
to paper.
|
Types
|
Personal and Office printers. Black and White or color printers.
|
Continuous (CIJ) and drop-on demand (DOD).
|
Serial Dot Matrix printers and Line Dot Matrix.
|
Price per page
|
USD 0.6 for black and white page. Much higher for a color page.
|
USD 0.20 color page; USD 0.4-0.5 black and white page.
|
Copies are quite cheap.
|
Cost for basic printer
|
Approximately USD 60-1000, depending on the size and use of the
printer.
|
Approximately USD 100-150
|
Basic cost of printer is quite expensive. Compared to an inkjet,
dot matrix can cost between two to ten times more.
|
Printing speed
|
20 pages a minute
|
6 pages a minute
|
30-550 characters per second.
|
Quality
|
Printing quality is adequate. Best for black and white.
|
Printing quality is good, specially for smaller fonts.
|
Printing quality is bad if printing images. In terms of text,
printing is fine.
|
Color Printing
|
Basic models only offer black and white, with higher models
providing color printing.
|
Yes provides color printing.
|
Limited color printing.
|
Black and White Quality
|
Black and white quality is adequate, best for bulk printing.
|
Black and white quality is excellent, specially with small
fonts.
|
Can print adequate quality images.
|
Color Quality
|
Color quality is a bit poor, with banding.
|
Color printing is sharp and excellent.
|
Only works best with low-res images.
|
Size
|
Smaller is available but is more common in larger sizes.
|
Smaller and more compact.
|
Size ranges depending on usage. New compact ones are also
available.
|
Features
|
Offers scanners and faxing machines built in. Has bigger input
trays, direct connecting facilities (wireless)
|
Can be used for wider range of papers (photo paper, vinyl,
self-adhesive papers), accurate photographic images, ink is not waterproof.
|
Used for a variety of purposes. Can print on various types of
papers.
|
Usage
|
Most commonly used for commercial purposes and places that
require black and white printing.
|
More commonly used for homes as the unit is smaller and ink is
cheaper.
|
Used to be used for office uses, but now only used by select
places such as banks.
|
Maintenance
|
Expensive
|
Cheaper
|
Expensive, parts are hard to come by.
|
Advantages
|
Prints faster, bigger input trays.
|
Quieter in operation, high print quality, no warm up time, low
cost per page
|
Cheaper to print as ribbon is cheap.
|
Disadvantages
|
More susceptible to paper jams. Toner is very expensive, print
quality for color is adequate, device itself is expensive, has health hazards
if not properly maintained.
|
Ink is expensive, issues with ‘intelligent’ ink cartridges,
lifetime of inkjet prints produced by aqueous inks is shorter, ink is not
waterproof, and nozzle is prone to clogging.
|
Initial purchase is expensive, maintenance is expensive, prints
is not fast, makes noise.
|
