Network Layers Model (Networking Basics) - Computerphile

An introduction to the foundational network layers model, explaining how data travels between computers through different abstraction layers. Covers the OSI model's seven layers and the TCP/IP model, breaking down responsibilities from application layer (email, web browsers) through transport layer (TCP/UDP), network layer (routing between any two machines globally), data link layer (single hops between routers), to physical layer (wires, radio waves). Discusses the 'narrow waist' concept where innovation happens easily at application and physical layers but is difficult at the core transport and network layers, and why this layered approach has remained largely unchanged since the 1970s.