Transcript Internet
Internet
Standard Grade Computing
Internet
• a wide area network spanning the globe.
• consists of many smaller networks linked
together.
Service
• a way of using the internet to perform
specific tasks
Services available on the Internet
Three main services:
World Wide Web
gives access to information in remote
computers through browsing or searching
Email
messages between computers
File transfer
to send or receive large files
Other services
Chat
a web site where users can take part in text
discussions with other users
Instant messaging
a program that looks for your friends online
and tells you that they can receive messages
Bulletin boards (forums)
an electronic notice board where users can
post, read, look at messages
Discussion group
geographically separated users with a
common interest hosted on a web site
Web logs
a web page made up of short entries in
chronological (time) order like a diary
On-line banking
On-line shopping
Video streaming
the process of receiving video images over
a network and displaying them on a
computer screen
Video Conferencing
uses communication links to conduct
meetings between people who are
geographically separated. Requires a
computer system and a webcam in each
location together with a network connection
To connect to the Internet you need:
computer system
modem
communications software eg. browser and
email client program
Internet Service Provider (ISP)
Internet Service Provider (ISP)
A company that provides a host computer
connected to the Internet which the user
can access. The host computer manages
communications and stores data such as
email and web pages
Modem
a piece of hardware that changes the
digital signals from a computer into
“telephone signals” which can be sent
along a normal telephone line. A modem
at the other end changes the signals back
into digital form for the receiving computer.
Internet ready computer – consists of:
• computer system
• internal modem
• communications software eg. browser
and email client program
Mobile Internet Technologies
Includes palmtops, laptops, mobile phones.
Do not need a mains power supply or
physical connection to the Internet, which
can be achieved using wireless networking
interface cards.
Dial-up connection
a wire connects the computer’s modem
socket to the telephone socket. The
communication software dials the ISP’s
number and establishes a connection to the
Internet.
Broadband connection
constantly connected to the Internet, much
faster access. Telephone can be used at
same time. More than one computer can be
connected to Internet at same time.
Another definition of online…
Online – connected to the Internet.
Offline – disconnected.
Downloading Software
Downloading
Receiving a file from a network (server or
individual computer) and saving it onto a
computer system.
Freeware
Totally free software that can be used on
any number of computer systems.
Downloading Software
Shareware
Free for a short trial period to let you try it.
After that you must either delete the software
or pay to continue using it. Some crucial
functions usually missing (e.g. save, print).
Commercial software
Must be paid for. Can only be used on one
computer without a special license. You
cannot legally make copies.
World Wide Web
Browser
• a program that allows the user to access
web pages (surf the net) eg. Internet Explorer
Web page
• a single document or file on the World Wide
Web
• identified by a unique URL (Universal
Resource Locator)
• can used to hold information in multimedia
form
World Wide Web
Hyperlink
Links Web pages, documents or files;
activated by clicking with the mouse.
HTML
Hypertext mark-up language. A special
language used to create Web pages.
Search Engine
A site designed to help you find information.
The user can enter keywords.
Simple Search
The user enters one or more keywords
Complex Search
Allows the user to refine a search by
restricting the search to only parts of the Web.
Most allow the use of AND ( +), OR, NOT ( - )
eg. mountain + scotland
The Big Bad World Wide Web
Is inhabited by?
Who controls it?
Who checks the information is correct?
Who has access
•to the WWW?
•to your data on the WWW?
Creating a web page
Simplest way is to use
• a wizard or
• a template
You can then
• enter your text
• add graphics
Creating a better web page
To create a more interesting page, add
• audio
• video
• hyperlinks using text or hotspots (A
defined area in a graphic containing a
hyperlink)
Present information using tables
Internet
Standard Grade Computing
End of presentation