Intranets, Internet & Extranets

1. Intranets, Internet & Extranets Chapter 3

2. This presentation covers: • The characteristics and purpose of: • Intranets • Internet • Extranets

3. Introduction • In the last lesson we looked at different types of networks in terms of geographical location. • LANs • WANs • Virtual Networks • Now we will look at what methods we can use across these types of network to access data and services.

4. Internet • Commonly mistaken for the World Wide Web. • The Internet is the infrastructure that the World Wide Web can run on. • The internet comprises of telecommunication devices that connect computers together: • Telephone lines • Cables • Mobile phones • Satellites • etc

5. Internet • The World Wide Web comprises of hypertext documents which connect together. • They can contain sound, images, text, movies and animation.

6. Internet • Because you can connect to the internet with any device that has an external communication link... • The internet is often called an Open Network. • It uses TCP/IP communication between devices. • TCP: Transmission Control Protocol • IP: Internet Protocol

7. Internet: Purpose • The internet provides users with a number of services including: • World Wide Web • Email • File Transfer • Internet Relay Chat (instant messaging) • Playing games

8. Internet: Purpose • Many of the services on the net can be accessed via web browsers. • However, sometimes you need specialist software to access some of the other services. • For instance...to upload this content to www.dolinski.co.uk I need to use an FTP program. • FTP: File Transfer Protocol.

9. Internet: Purpose • The image below shows a file being updated from my PC to my website via an FTP application.

10. Intranets • This provides the same services as the internet but on a closed network. • Many companies use the same technology that the internet uses to transfer files across departments. • An intranet can run on a LAN or across a virtual network using a WAN.

11. Intranet: Purpose • Similar to that of the internet only that it provides: • Internal email • Internal web Pages • Internal chat • File transfer • Gaming (if you are allowed!!)

12. Intranet: Purpose I can’t see what’s being transferred! • Many companies, such as schools, put important company documents on their intranets. • This has allowed companies to cut down on paper costs. • Security is also improved as important documents can be transferred safely within the network. Intranet Server A baddy!

13. Extranet WOOT! I have access! • This is basically an intranet that allows outside access! • A user will need an internet connection to connect to the intranet. • To gain access they will need to provide some security information such as username and password. Intranet Server A Goody!

14. Extranets • These provide employees a little more flexibility and allows them to work from home in some cases. • Files can be kept confidential but there is still some risk that the network could be hacked as it does allow connections from the internet.

15. Activity • Study the table on page 73 and 74 of the text book which summaries the characteristics and the purposes of the internet, intranets and extranets. • Once you have looked at the table, close the book and see how many you can write down without looking. • If you can remember at least 3 characteristics and 3 purposes for each one you are well on your way to remembering all of them!! 

16. Activity • Bonus History Points! • Can you find out the original purpose of the internet? Where did it come from and why was it made?