The document discusses key concepts related to how the internet works, including domain names and IP addresses, data packets and packet switching, and routers. It explains that domain names are used to identify websites while IP addresses are numeric labels assigned to devices on a network. It also describes how data is broken into packets that are routed through networks and defines routers as devices that read packet destinations and direct packets along the fastest available path between networks.

1. The Internet – Packets, Routers & IP
Addresses
Definition of The Internet…
A global computer network providing a variety of information and communication facilities,
consisting of interconnected networks using standardized communication protocols – Google
A vast computer network linking smaller computer networks worldwide(usually
preceded by the). The Internet includes commercial,
educational, governmental, and other networks, all of which use the
same set of communications protocols – Dictionary.com

2. Domain Names & IP Addresses
What is the relationship between domain names and IP addresses?
The domain name system is an internet service that translates domain names to IP addresses. This is one
of the crucial services on the internet, it allows users to access the desire website by typing its alpha-numeric
name (domain name) in the browser, instead of its real numeric system name (IP address).
What is a domain name?
Domain name system (DNS) is the most recognisable system for assigning addresses to Internet web
servers. The domain name system helps to give every Internet server a memorable and easy-to-spell
name. The domain system usually keep the very technical IP address invisible for most users. Eg.
Wikipedia.org, About.com
What is an IP address?
An Internet protocol address (IP address) is a numerical label assigned to each device (Eg. Computer,
printer) participating in a computer network that uses the Internet protocol for communication. For
simplicity purposes, the IP address is replaced with a domain name so that it is easily recognisable.

3. Data Packets & Package Switching
What is a data packet?
Definition - A packet is a basic unit of communication over a digital network. A packet is also called a
datagram, a segment, a block, a cell or a frame, depending on the protocol. When data has to be
transmitted, it is broken down into similar structures of data, which are reassembled to the original data
chunk once they reach their destination.
What is packet switching?
Definition – packet switching describes the type of network in which relatively small units of data
called packets are routed through a network based on the destination address contained within each
packet. Breaking communication down into packets allows the same data path to be shared among
many users in the network.

4. Function of Routers
What are routers?
A router is a device that transfers data from one network to another, doing so in a very intelligent way. It
has the important task of forwarding data packets to their destination via the most efficient route.
When a data packet arrives, the router does the following…
•Reads the data packet’s destination address
•Looks up all the paths it has available to get to that address
•Checks on how busy each path is at the moment
•Sends the packet along the least congested (therefore fastest) path
Routers are also needed to enable computers to connect to the Internet because the Internet is such a
vast external network.

5. Useful websites I used…
•Dictionary.reference.com
•www.ntchosting.com
•Netforbeginners.about.com
•Wikipedia.org
•Voip.about.com
•Searchnetworking.techtarget.com
•www.teach-ict.com