1. Computing Fundamentals 1
01/08/2018
Computing Fundamentals 1
The Internet

2. 01/08/2018
What is the Internet?
A global network connecting millions of computers (from more than 100 countries).
Used to exchange data, news and opinions, as well as perform electronic business
Each computer that is connected to the internet is called a host and is independent

3. Internet Design & History
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Internet Design & History
Internet was designed by the US Military 1960’s
In-built multiple redundancy
If data can’t get down one link, it will try and go around the problem
Wider academic use occurred later
1980’s uniform protocols developed
1990’s widespread take-up of the technology

4. Capabilities of the Internet I
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Capabilities of the Internet I
Communicate
Usenet (worldwide discussion groups)
Chat (live and interactive discussions)
Mailing Lists
Telnet (means of remotely accessing a computer from any other computer on the Internet

5. Capabilities of the Internet II
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Capabilities of the Internet II
Retrieve
File Transfer Protocol (FTP) – allows connection to a computer on the Internet and transferring files from it to your computer (also allows uploads, but this requires account information)
World Wide Web (WWW) – websites and web pages: billions of pages of information stored on the internet

6. What is the difference between an Intranet and the Internet?
01/08/2018
What is the difference between an Intranet and the Internet?
An intranet is a network that is accessed by the people within an organisation
Intra means ‘on the inside, within’
Will essentially refer to the local part of the network that is separated from the internet by a firewall, router etc.
The internet refers to the whole worldwide publicly available network

7. Types of Internet Data Text Hypertext Mark-up Language (HTML)
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Types of Internet Data
Text
Hypertext Mark-up Language (HTML)
Web pages
Internet Relay Chat (IRC)
Chat rooms
Newsgroups s
Multimedia (images, sound, animation)

8. Internet Addresses Each computer has an IP (Internet Protocol) address
01/08/2018
Internet Addresses
Each computer has an IP (Internet Protocol) address
IPv4 comprised of four groups of up to three numbers (1-255) separated by dots
Example:
IPv6 – Eight groups of four hexadecimal digits.
Example: 2001:0DB8:85A3:0000:0000:8A2E:0370:7334

9. Domain Names IP addresses is the basis for transmission
01/08/2018
Domain Names
IP addresses is the basis for transmission
Names given to be more user friendly
Servers can resolve between domain names and IP addresses from local lists, or if name or number not listed a global list from a DNS (Domain Name Server)
Example of a domain name
greenwich.ac.uk

10. Domain Name System hierarchy
Sample of the Domain Name System hierarchy, starting from the root “ . “
Each domain name is composed of one or more labels e.g.
Country: .de = Germany, .uk = United Kingdom
UK company e.g.: .co.uk
Commercial organisation e.g.: sun.com
The list is endless

11. Top-level domain (TLD)
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Top-level domain (TLD)
Top-level domain names allow us to identify the type of domain
.com = commercial operation or business (usually US sites, but not necessarily).
In some countries (including the UK) .co is used instead of .com
.org = organisations – charities, professional associations that operate on a non-commercial basis
.edu = educational institution, normally universities
In some countries (including the UK) .ac is used instead of .edu
.gov = government
.net = internet service provider (ISP)

12. Domain Name Example www.gre.ac.uk A site in the United Kingdom (.uk)
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Domain Name Example
A site in the United Kingdom (.uk)
Educational institution (.ac)
“gre” is the name or abbreviation representing the institution’s web space
“www” denotes a web server

13. Subdomains No real limit to number of sub-domains
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Subdomains
No real limit to number of sub-domains
address is read right to left (i.e. subdomain.domain.com)
Each domain knows the location of it’s sub-domains
e.g. java.sun.com – java is the subdomain which is part of the root domain sun.com

14. Accessing the Internet
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Accessing the Internet
Computer connected directly through a permanent connection (e.g. Intranet connected to Internet)
Modem that dials an Internet Service Provider (ISP) eg. BT, FreeServe
Access bandwidths:
Standard connection (up to 57,600 bps)
ISDN (64,000 bps – 1.5 Mbps)
ADSL (1.5 – 9 Mbps)

15. 01/08/2018
World Wide Web (www)
A system of Internet servers that supports specially formatted documents
Originally a text based service, developed into graphical system
Cross-platform
Low bandwidth (quick to load!)
Fastest-growing part of the Internet

16. Internet ≠ World Wide Web I
01/08/2018
Internet ≠ World Wide Web I
The Internet and the WWW are not the same
The Internet is a massive network of networks, a networking infrastructure.
The World Wide Web is a way of accessing information over the medium of the Internet. It is an information-sharing model that is built on top of the Internet.

17. Internet ≠ World Wide Web II
01/08/2018
Internet ≠ World Wide Web II
Examples of other Internet uses:
FTP – File Transport Protocol, used to transfer files directly between computers
SMTP – Simple Mail Transport Protocol, used to send s

18. Web Pages Interconnected electronic documents Actually text files
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Web Pages
Interconnected electronic documents
Actually text files
Contain formatting tags to define
Formatting
Images
Links to other pages (hyperlinks)
Other variations exist (XHTML)

19. Example of a HTML file <html> <head>
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Example of a HTML file
<html>
<head>
<title>Hello World HTML example</title>
</head>
<body>
<p>Hello world</p>
<img source="img/HelloWorld.gif">
</body>
</html>

20. Viewing Web Pages - Browsers
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Viewing Web Pages - Browsers
To view web pages a browser is required
A browser interprets the web page and displays it
Examples of browsers:
Internet Explorer
Google Chrome
Netscape Navigator
Firefox
Opera

21. Security By default information is transmitted as sent
01/08/2018
Security
By default information is transmitted as sent
Possible to examine packets passing through the internet and read contents
Methods available for encryption
Secure Sockets Layer (SSL)
Address is rather than
Also look for the yellow padlock icon. It is recommended that you don’t supply details such as your credit card number if this is not showing

22. 01/08/2018
Favourites
Web addresses of pages that you visit often can be stored, by adding them to the Favorites list.
Can be organised into folders
Favourites
To add a page to Favorites in IE:
Choose Favorites /Add to Favorites from the menu
Or:
2. Click on the Favorites icon from the tool bar and then click “Add to favorites”…

23. 01/08/2018
History
The addresses of the web pages you visit are stored on the computer in the History folder for a certain period of time.
It is expressed in days, from 0 to 999
It can be changed by going to:
Tools > Internet options > Browsing History Settings

24. Temporary Internet Files
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Temporary Internet Files
The web pages you visit, including images, sounds, animations, etc. are stored in locally on the computer in a Temporary Internet Files folder.
Storing the files locally means that they don’t have to be downloaded from scratch every time you visit the page.
Go to Tools > Internet Options > Browsing history… to delete or change the Temporary Internet Files settings

25. Task for next week: In preparation for your coursework:
01/08/2018
Task for next week:
In preparation for your coursework:
You will be writing about a famous person of your choice
All students please me the name of the famous person that you intend to write about
Sports personalities and actors are not allowed i.e. Michael Jordan, Jackie Chan, Mohammed Ali, Paris Hilton, Sachin Tendulkar, Wasim Akram and Steven Gerrard etc.

26. Choose from one of the following:
A writer
An astronomer
A composer
An anthropologist
A painter
A botanist
A mathematician
A zoologist
A philosopher
An inventor
A physician
An architect
A chemist
A computer scientist
An economist
A sociologist
A geologist
The course web page is: