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Networks and the internet
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When you send a message, it travels across networks to the other side of the world in a fraction of a second. Here is how.
Networks
A network is two or more computers connected so they can share data and resources.
A LAN (local area network) covers a small area, such as a home or school.
A WAN (wide area network) covers a large area. The internet is a huge WAN: a network of networks.
A router sends data between networks; a switch connects devices within a LAN.
A LAN (local area network) covers a small area, such as a home or school.
A WAN (wide area network) covers a large area. The internet is a huge WAN: a network of networks.
A router sends data between networks; a switch connects devices within a LAN.
Packets and addresses
Data is split into small pieces called packets.
Each packet carries the IP address of where it is going, where it came from, and its number in the order.
Packets may take different routes and are put back in order when they arrive.
The DNS (domain name system) turns names like gov.uk into IP addresses that computers use.
Each packet carries the IP address of where it is going, where it came from, and its number in the order.
Packets may take different routes and are put back in order when they arrive.
The DNS (domain name system) turns names like gov.uk into IP addresses that computers use.
The internet and the web
The internet is the hardware: the connected networks, cables and routers.
The World Wide Web is the collection of web pages you visit using a browser. It runs on the internet.
Email and online games use the internet too, but they are not part of the web.
HTTPS sends web pages securely, encrypted so others cannot read them.
The World Wide Web is the collection of web pages you visit using a browser. It runs on the internet.
Email and online games use the internet too, but they are not part of the web.
HTTPS sends web pages securely, encrypted so others cannot read them.
Explain how a photo travels from your phone to a friend's phone.
- The photo is split into packets.
- Each packet has your friend's address and a packet number.
- Routers forward the packets across networks, possibly by different routes.
- Your friend's device puts the packets back in order.
Answer: It is split into numbered, addressed packets, routed across networks and reassembled at the other end.
A LAN covers a small area; a WAN covers a large area, and the internet is a network of networks. Data travels in addressed packets, and DNS turns web addresses into IP addresses. The web runs on the internet.
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