Internet –
Computer Awareness Notes
Internet
The Internet is
a global system of interconnected computer networks that use the standard
Internet protocol suite (TCP/IP) to link several billion devices worldwide. It
also known as “network of networks” that consists of millions
of private, public, academic, business, and government networks.
Internet Work: In Internet, most computers are not
connected directly to the Internet. Rather they are connected to smaller
networks, which in turn are connected through gateways to the
Internet backbone.
Gateway: A
gateway is a device the connects dissimilar networks.
Backbone: A
backbone is central interconnecting structure that connects one or more
networks just like the trunk of a tree or the spine of a human being.
Who governs the Internet ?
Internet is not governed
by the any particular body. It is coordinated by many volunteer organizations.
- The Internet
Architecture Board(IAB) is responsible for approving standards and
allocating resources.
- The Internet Engineering
Task Force (IETF) is responsible for discussing and investigating
the operational and technical problems of Internet.
- The InterNIC is
responsible for providing registration services to Internet community.
Internet Function
The World Wide
Web commonly known as the Web or www developed founded by Tim
Berners – Lee in 1989, is a system of interlinked hypertext documents
that are accessed via the Internet. These multimedia pages are ever-changing.
- A web browser (commonly
referred to as a browser) is a software application for retrieving,
presenting and traversing information resources on the World Wide Web.
Various Applications of Internet are:
- Exchange messages using e-mail
(Electronic mail).
- Transfer files as well as
software.
- Browse through information on
any topic on web.
- Communicate in real time (chat)
with others connected to the Internet.
- Search databases of government,
individuals and organizations.
- Read news available from leading
news groups.
- Send or receive animation and
picture files from distant places.
- Set up a site with information
about your company’s products and services.
The seeds of Internet
were planted in 1969, when US Department of Defense sponsored a project named
ARPANET .
Connection Of Internet:
Through Dial-up Connection: A dial us connection is a temporary
connection, set up between your computer and ISP (Internet Service
Provider)server. A dial-up connection is established using a modem, which uses
the telephone line to dial up the number of ISP server.
Through Broadband
Connection: The term broadband is short for broad
bandwidth. Bandwidth refers to the amount of data that a signal or circuit can
carry. Broadband connection speeds are measured in megabits per
second (mbps).
Wireless Connection : These days we can also connect to
Internet wirelessly.
- Wi-Fi: It refers to Wireless
Fidelity, which lets you connect to the Internet without a direct line
from your PC to the ISP.
- WiMAx: It is a wireless digital
communication system. WiMAX can provide broadband wireless access (BWA) up
to 50 km for fixed stations
Various features of a Web Browser are:
Command
|
Function
|
Home
|
Opens or returns to starting page
|
Back
|
Takes you to the previous page
|
Forward
|
Takes you to the nest page
|
Print
|
Prints current page
|
Stop
|
Stops loading a page
|
Reload
|
Refresh / redisplays current page
|
Search
|
Access search engine
|
- Menu bar: The menu bar, located at the
very top of the screen, can be accessed using the mouse. Actions that are
in black can be performed, while actions that cannot be performed will be
in gray or lightened.
- Tool bar: The tool bar is located at the
top of the browser; it contains navigational buttons for the Web. Basic
functions of these buttons include:
- Location bar: The location bar, below the tool
bar, is a box labelled "Location," "GoTo," or
"Address." You can type in a site's address, and press the
Return or Enter key to open the site.
- Status bar: The status bar is located at the
very bottom of the browser window. You can watch the progress of a web
page download to determine if the host computer has been contacted and
text and images are being downloaded.
- Scroll bar: The scroll bar is the vertical
bar located on the right of the browser window. You can scroll up and down
a web page by placing the cursor on the slider control and holding down
the mouse button.
- A website is a
set of related web pages served from a single web domain.
- The Uniform Resource
Locator, abbreviated as URL is the Address for web sites. Most of them
begin with http (Hyper Text Transfer Protocol), followed by a colon and
two slashes.. In most web browsers, the URL of a web page is displayed on
top inside an address bar. An example of a typical URL would be"mentorforbankexams.com".
- A Home page, index page, or main
page is a page on a website. A home page usually refers to:
- A Hyperlink is
a reference to data that the reader can directly follow either by clicking
or by hovering or that is followed automatically.
- Downloading means to receive data to a
local system from a remote system, or to initiate such a data transfer.
- Uploading refers to the sending of
data from a local system to a remote system such as a server or another
client with the intent that the remote system should store a copy of the
data being transferred.
- An email attachment is
a computer file sent along with an email message. One or more files can be
attached to any email message, and be sent along with it to the recipient.
The first email was sent byRay Tomlinson to himself in 1971.
- CC (Carbon Copy) in e
– mail indicates those who are to receive a copy of a message addressed
primarily to another. The list of CCed recipients is visible to all other
recipients of the message.
- An additional BCC (blind
carbon copy) field is available for hidden notification;
recipients listed in the BCC field receive a copy of the message, but are
not shown on any other recipient's copy (including other BCC recipients).
- The Drafts folder retains
copies of messages that you have started but are not yet ready to send.
- Hotmail, a free e-mail service provided
by Microsoft which was established in 1995 was co - founded by an Indian
American entrepreneur Sabeer Bhatia along with Jack Smith in July of 1996.
- An Internet Protocol
address (also known as an IP address) is a numerical
label assigned to each device (e.g., computer, printer) participating in a
computer network. It acts as an identifier for a computer. It is a unique
address for every computer.
- Top-level domain: Each part of a domain name
contains certain information. The first field is the host name,
identifying a single computer or organization. The last field is the
top-level domain, describing the type of organization and occasionally
country of origin associated with the address. For e.g. - .com –
Commercial, .edu – Education.