How the Internet Works infographic - TCP/IP, DNS, HTTP, and how data travels the web

Click image to open full size

Computer Science

How the Internet Works

TCP/IP, DNS, HTTP, and how data travels the web

Download PNG Save to Pinterest

Related Tools

Related Labs

Related Worksheets

Related Cheat Sheets

The internet is a worldwide network of networks that lets devices exchange data using shared rules called protocols. When you open a website, your device does not send one giant message in a straight line. Instead, data is split into packets that travel through routers, cables, wireless links, and servers. Understanding this process helps explain speed, reliability, security, and everyday tools like search, streaming, and messaging.

A web request usually starts on your device, passes through your local Wi-Fi router, enters your internet service provider network, and then moves across larger backbone networks toward a website server. DNS translates a human-readable domain name into an IP address, while protocols such as TCP, IP, HTTP, and TLS organize delivery, addressing, content, and encryption. Routers choose paths for packets based on network conditions and routing tables. The server sends packets back, and your device reassembles them into the page you see.

Key Facts

  • The internet is a packet-switched network, meaning data is divided into small packets before being sent.
  • An IP address identifies a device or server on a network, such as 142.250.190.14.
  • DNS converts domain names into IP addresses, for example example.com to 93.184.216.34.
  • TCP helps reliable delivery by using sequence numbers, acknowledgments, and retransmission.
  • HTTP and HTTPS define how web browsers request and receive web pages, images, and files.
  • Total transfer time can be estimated as time = data size / bandwidth plus latency delays.

Vocabulary

Packet
A packet is a small unit of data that contains part of a message plus addressing and control information.
Router
A router is a network device that forwards packets toward their destination using routing information.
IP Address
An IP address is a numerical label used to identify a device or server on a network.
DNS
DNS is the system that translates domain names into IP addresses so computers can locate servers.
TLS
TLS is a security protocol that encrypts data between a client and server, commonly used in HTTPS.

Common Mistakes to Avoid

  • Thinking the internet is the same as the World Wide Web is wrong because the web is only one service that runs on the internet.
  • Assuming packets all take the same route is wrong because routers can send different packets along different paths depending on traffic and network conditions.
  • Forgetting DNS lookup time is wrong because a browser often must find the server IP address before it can send the web request.
  • Confusing bandwidth with latency is wrong because bandwidth measures data rate, while latency measures delay before data begins arriving.

Practice Questions

  1. 1 A 12 MB image is downloaded over a connection with a bandwidth of 24 Mbps. Ignoring latency, how many seconds does the download take?
  2. 2 A web page requires 8 packets to be sent from a server to a browser. If each packet is 1500 bytes, how many total bytes are transmitted for the page data?
  3. 3 Explain why a website can still load even if one router on the internet fails, and name the networking idea that makes this possible.