5.1 The Internet

What the Internet Is

The Internet is a global network of interconnected computing devices called routers and hosts. It uses fault-tolerant design, meaning it keeps working even if individual paths or devices fail. Data moves between devices using standardized rules called protocols, which allow devices from different manufacturers to communicate reliably.

Packets and Protocols

Messages are broken into packets — small chunks of data sent independently and reassembled at the destination. TCP (Transmission Control Protocol) handles breaking data into packets and reassembling them, while IP (Internet Protocol) handles addressing and routing packets to the correct destination. Together, TCP/IP enables reliable data transmission across the Internet.

Scalability and Bandwidth

The Internet's design is scalable, meaning it can grow to support more users and devices without a central point of control. Bandwidth is the maximum amount of data that can be sent in a fixed amount of time, often measured in bits per second. Higher bandwidth allows faster data transfer, but latency and network congestion can still affect performance.

Key terms

Internet

A global network of interconnected computing devices that communicate using common protocols.

Fault-tolerant

Describes a system that continues to operate properly even when some components fail.

Packet

A small unit of data sent independently across a network and reassembled at the destination.

TCP/IP

TCP breaks data into packets and reassembles them; IP handles addressing and routing packets to their destination.

Bandwidth

The maximum amount of data that can be transmitted in a fixed amount of time, often in bits per second.

Try an AP-style question

Why were the Internet's protocols made open and nonproprietary?

1. So it would be slower
2. So one company could control it
3. So it couldn't grow
4. So anyone could build compatible devices