Week 2 - What is the Internet

The Internet is quite simply one large system of connected computers and associated controlling devices. For example, a set of computers are linked to servers, the servers are then connected to other servers which are linked to other computers, when all machines are linked and connected we have the internet.

There are different types of networks within the internet. The vast majority are client/server, such as this blog site, my computer (the client) requests information from www.blogger.com (the server) which passes the information back to my computer, this takes place via the web browser.

Peer to Peer networks are also within the internet, a peer to peer network operates by allowing each computer on the network to be the client and the server, thus creating a peer relationship and ultimately one giant super network, the more computers that are connected to the peer to peer network the greater the capacity will be of that network. Torrent sites are good examples of peer to peer networks as is Skype.

The transmission and reception of information on the internet is performed by a set of various protocols that have been developed to provide the movement of information from one part of the internet to another whilst maintaining the integrity of that information.
The most common protocol and the most important is the TCP/IP protocol, which is actually two protocols.

TCP stands for Transmission Control Protocol and this protocol is responsible for breaking information down into packets that get sent across the internet to the receiving computer at which point the TCP reassembles the information into its original form.

IP stands for Internet Protocol and this protocol controls the movement of information on the internet. Every computer on the internet has an IP address which is a series of unique numbers, much like a postal address.

As humans it is easier for us to remember and relate to the alphabet rather than a series of numbers, therefore some IP addresses on the internet have Domain Names applied to them for ease of reference. There are different levels of Domain Names, Top level domains denote things such as the Country name for example ".com .au .de". Second Level domains denote what the address is, for example Google or a company name. Domain names are controlled by Domain Name Servers, these servers are spread throughout the world and each time you type in a URL (Universal Resource Locator) a Domain Name Server is used to provide the right IP address to get you to where you want to go.

As the internet has expanded so to has the need for increased bandwidth. Bandwidth refers to the amount of available resources to communicate data. The higher the bandwidth, the larger amount of information that can pass through, thus the faster the communication can occur. Internet Bandwidth is measured in bits per second. A bit is the smallest measurable binary unit for a computer. One bit is equal to the 1 or the 0 by which computers talk. 8 bits equal 1 byte.