The document discusses key concepts related to how information is transmitted on the internet. It explains that domain names provide a human-friendly way to access websites, which are located via their underlying IP addresses. It also describes how files sent over the internet are broken into packets, with each packet containing a header with the destination IP address and packet number. Routers then direct these packets through the internet, ensuring the packets reach the correct destination.

1. Packets, Routers
and IP Addresses
Computing ELT Two

2. What is the internet?
 a global computer network providing a variety of information and
communication facilities, consisting of interconnected networks using
standardized communication protocols
 Google’s definition of the internet.

3. Domain Names and IP Addresses
 A domain name is the address that is typed into a web browser to get to a
website. This then takes you to the ‘real address’ which sends you to your
website. (The ‘real address’ is called the IP address; this is a series of
numbers and dots such as 123.45.678.91.) After that, the IP address takes
you to the location on the server which contains the files and information for
the website that you want to go to.
 We mainly use domain names rather than IP addresses when going to a
website because a simple name is usually much easier to remember than a set
of digits.

4. Data Packets and Packet Switching
 When a file is sent to something else (for example, an email sent to another
country), it is separated into ‘data packs’. Before each data pack is sent, it is
given a ‘header’ which contains the IP Address for this part of the file. The
‘header’ also gives each of the packets an individual number and records how
many data packets that the file was split up into.

5. The Function of Routers
 Routers are used to perform ‘traffic direction’ on
the internet. Data packets are sent between
routers within the internet until it reaches the set
destination. Moreover, routers make sure that
data does not end up anywhere where it was not
originally intended to go.

6. Sources of Information
Teach ICT
HowStuffWorks
Wikepedia
Google Images