Key words and notes for revision 1

The internet is the whole network of networks that’s sends information along thousands of different global paths to other computers.

The web is a small part of the internet that is comprise of webpages, multimedia, text and things that use HTML as structure and transportation.

The intranet is a miniature internet that is private to a network. That can only be accessed internally like the school network.

The extranet is a part of the intranet that has been published to the public like the schools Jogport.

A router is a specialise computer that knows enough about its local part of the internet to send packets generally to the right direction to get to the wanted location. There are many of these to redirect info at each junction of the internet.

Packets are small amounts of data that were part of a larger data e.g.  a document  that has been downloaded. They are broken down into three parts:  The header-this contains the sender’s and receiver’s ip address and the packet sequence; the payload that contains the broken down information and finally the trailer that checks for errors during the send and receive process. 

The domain name is for the use of people to be an easily remembered instead of the ip address. Composed of a top level domain followed by sub domains (first level, second level etc….) working from right to left.

The ip address   is the computers version of a domain name that is binary; they are 8 bite binary number. Every computer has a unique ip address to stop packets from going to the wrong computer.

Domain name server translates the human domain name to the computers ip addresses to locate .They are scattered all over the internet and are constantly updated.

Isp or internet service provider are people like sky that provide you with an internet connection.

Internet registries are people that check for availability of ip addresses and hand them out.

Internet registrars’ are the people who monitor domain name and the people who you buy the rights to a domain name.

URI stands for uniform resource identifier and is the general term for unique identification

URL stands for uniform resource location and uses the specific location in the website address bar for instance

The client is a computer on a network that is sending the request for the resources off the internet from another computer e.g  your computer asking a website to download a file.

The server is the computer on the network that the client is asking for the resources, it is made up from many small computers to make towers.

TCP/IP is code for Transition Control Protocol over the Internet Protocol and are responsible for together moving info around the internet.TCP breaks down the information and turns it into packets of data and transmits it. The IP is responsible for finding other computers and rerouting it around the internet. The TCP/IP can be broken down into 4 layer and is call the TCP/IP protocol stack. The 4 layer are:

The application layer- this is the specific networking application e.g a web browser.

The Transport Layer - this layer breaks the data into small packets and in the header adds the source and destination ports and the packet sequence

The network layer- this layer adds the source and destination IP address to the headers in the packets

The link layer-this layer adds the MAC address to the packet and puts the data on the cable to the nearest router on the network

Here are some common protocols and their port numbers. (sourced for Mr.Klines' Powerpoint)