Objectives
By the end of this lesson you will be able to…
- Understand what the Internet and World Wide Web are, and how they differ.
- Identify the components of a web address.
- Understand what a protocol is, and the use of HTTP for transferring web pages.
- Understand the purpose of DNS servers.
- Understand how packet switching works, and simulate it to send information.
Starter
Click each card to reveal the answer.
Web addresses
A web address is technically called a Uniform Resource Locator (URL). It identifies a file on the Internet. Click each coloured part below.
Click a part of the URL to learn what it is.
Top-level & second-level domains
Click a domain on the left, then click its matching meaning on the right.
IP addresses
An IP address (Internet Protocol address) identifies a particular computer on the Internet, like a house number identifies a particular house.
An IP address is four numbers separated by dots. Each number must be between 0 and 255. For each of these, decide whether it's a valid IP address:
DNS servers
The Domain Name System links domain names to IP addresses. A DNS server translates a friendly name into the IP your computer actually needs.
Packet switching
To travel across the Internet, data is split into packets. Each packet is numbered and may take a different route, so packets can arrive at different times, then they're reassembled in order.
An image is also just data, so it gets split into packets too.
A file is split into 10 packets. Routers send each packet along the fastest open route, not necessarily the shortest one. Different packets can take different paths depending on live traffic and outages, and they reroute instantly around any link that goes down.
Arriving (out of order)
Reassembled message
Plenary
Click each term to reveal the definition. Then explain each to a partner.
🎉 End of Lesson 1