TCP/IP

TCP/IP is the foundational protocol suite of the Internet, combining two distinct functions into a layered architecture. IP (Internet Protocol) handles addressing and routing: it assigns unique addresses to devices and defines how packets are forwarded across network boundaries. TCP (Transmission Control Protocol) handles reliable delivery: it breaks data into packets, ensures they arrive in order, detects errors, and requests retransmission when packets are lost.

Developed by Vinton Cerf and Robert Kahn in the 1970s, TCP/IP replaced earlier network protocols with a design that was intentionally simple at the core and extensible at the edges. The layering — separating the network layer (IP) from the transport layer (TCP) — enables the Internet to absorb new physical technologies without changing the logical addressing scheme, and enables applications to treat the network as a reliable pipe without knowing its internal structure.