The document discusses key concepts relating to how information is transmitted on the internet. It explains that the internet is made up of interconnected computer networks. It describes how domain names are linked to unique IP addresses to identify devices. It defines data packets as the basic units of communication that are routed between networks, and explains how routers read address information in packets to determine the destination and direct packets accordingly.

1. Packets, routers and IP
addresses
The internet is made up of millions upon
millions of small computer networks all
brought together to form a vast “Inter-
Network”. It was shortened to the much
easier to say “Internet”.

2. The link between Domain names and
IP addresses
The link between a IP address and a domain name is that every
server has a Domain name and then that server serves to other
computer or desktops. Every single laptop and computer has a IP
address and every code or set of numbers is unique like a licence
plate.

3. Data Packets and Packet Switching
Data Packets:
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.
Packet Switching:
Packet-switched 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.

4. The Function of Routers
A router is a networking device,
commonly specialized hardware, that
forwards data packets between
computer networks. This creates an
overlay internetwork, as a router is
connected to two or more data lines
from different networks. When a data
packet comes in one of the lines, the
router reads the address information
in the packet to determine its ultimate
destination. Then, using information in
its routing table or routing policy, it
directs the packet to the next network
on its journey.

5. http://en.wikipedia.org/wiki/Router_(computing)
http://www.teachict.com/technology_explained/server/server.html
http://netforbeginners.about.com/od/d/f/domain_name.htm