REVISION

REVISION

1. The application layer consists of applications/programs and processes that use the network. Consists of FTP (File Transfer Protocol)

2. WAN- Wide Access Network. Used when devices are over 2km apart; the internet is an example of a WAN. WAN's cover a large geographical area and are often made from several LAN's connected together.

3. LAN- Local Area Network; covers a small geographical area and are often used in homes or small offices.

4. Client server- a form of computer networking where the data or web application is hosted on a server or accessed by client computers.

5. Peer to peer (P2P)- A type of network model where all computers on the network share responsibility and there is no single central server.

6. Topologies are the way in which computers on a network are arranged. This includes the following: star, bus, mesh, ring and fully meshed.

7. Star topology: The most common way of arranging a LAN and hosts are connected to a central hub or switch. If one device goes down, the whole network won't crash as well and it is easy to add new nodes. A disadvantage is that, if the central devices goes down, the whole network will as well.

8. Mesh topology: Each node is connected to 2 or more other nodes and can be a partial mesh or fully mesh. An advantage is that a broken node won't affect the transmission of data, but it requires continuous supervision.

9. Ethernet: a copper cable used to connect computers to a network. Is a lot faster than WIFI, as it provides a direct connection through wiring.

10. WIFI is wireless, meaning it does not use cables/wires to connect to a network. Instead, it transmits data through radio signals. A wireless NIC is needed for this type of connection and wireless can be intercepted by anyone in range, meaning it is not the most secure.

11. Protocols: a set of rules for how messages are turned into data packets and sent across a network. Includes: FTP, POP, IP, HTTP, HTTPS and more.

12. FTP: a protocol used to transfer large files across the internet. It is often used for organising files on a web server for a website. You can have private access to an area on an FTP server where you can upload your files.

13. HTTP transfers web pages from web servers to the client. All web page addresses start with http. An https address is a secure web address which has been encrypted. An https address is used for sites holding bank details and secure information.

14. The Open Systems Interconnection model is a conceptual model that characterizes and standardizes the communication functions of a telecommunication or computing system without regard to its underlying internal structure and technology.

15. Packet Switching- data is split up into many small packets and then sent across the network on different routes. Routers forward the packets on. When the journey is finished, all of the packets are organised back together to the origional data.