The document discusses key concepts relating to how the Internet works. It defines the Internet as a global network of interconnected computer networks that use standard protocols to share information. It describes how IP addresses identify devices connected to the Internet and how domain names make addresses easier for humans to use, with domain name servers translating names to IP addresses. It also explains how data is broken into packets and sent over networks, with routers selecting the best path to direct packets to their destination while allowing for rerouting if issues arise.

1. The Internet

2. Definition
Internet
ˈɪntənɛt/
Noun
a global computer network providing a variety of information and
communication facilities, consisting of interconnected networks using
standardized communication protocols.
Source: www.google.com

3. Domain Names and IP Addresses
• An Internet Protocol (IP) address is a unique set of numbers given to a
device which connects to the internet to identify it.
• IP addresses are used in the same sort of way as postal addresses, as
they are used to send data to specific devices, just as you would a
letter to a house.
• Domain names are used as they are easier for humans to use. They
are what you type in to the address bar on your browser to connect to
a website.
• When you type in a domain name (eg www.google.com) it is sent to a
domain name server (DNS) which finds the correct IP address to get
you on to the website.
Source: www.howstuffworks.com

4. Data Packets and Packet Switching
• Data Packets are pieces of information that have been broken up into
separate bits. The size of the packets typically range from 512 bits
upwards.
• The packets travel through the network and are reassembled in the
correct way on the receiving device.
• Packets are used as they are more reliable; if there is a problem in a
network, they can be diverted around it. Also, if one is missing, the
device only needs to ask for the particular one to be resent.
Source: www.webopedia.com

5. Routers
• Routers are used to transfer data from network to network. It
transfers data in the most efficient way to it’s destination.
• It does this by looking at the data’s destination and finding the least
congested route to send it down.
• Routers can also filter information (to find malware etc) and
exchange protocol information across networks.
Source: www.teach-ict.com