TCPIP

TCP/IP, short for Transmission Control Protocol/Internet Protocol, is a suite of communication protocols used for the Internet and other networks. It specifies how data should be packetized, addressed, transmitted, routed, and received. The core idea is end-to-end communication across networks that may differ in hardware and software. The protocol family originated in the 1970s as part of the ARPANET project and was developed by Vint Cerf and Robert Kahn. It is defined and maintained by the Internet Engineering Task Force (IETF) and related standards organizations.

The two central protocols are TCP and IP. IP handles addressing and routing of packets from source to destination. It is a best-effort, connectionless protocol. TCP provides reliable, ordered delivery of streams of data, using sequencing and retransmission. UDP offers a lighter, connectionless transport for low-latency applications without guarantees. The suite also includes ICMP for diagnostics, ARP for mapping IP addresses to MAC addresses on local networks, DHCP for dynamic addressing, and DNS for translating domain names into IP addresses.

The TCP/IP model has four layers: link, Internet, transport, and application. The Internet layer corresponds to IP functionality, while the transport layer carries TCP and UDP. The application layer includes protocols such as HTTP, FTP, and SMTP. IPv4 and IPv6 exist; IPv6 provides a larger address space and modern features, though IPv4 remains widespread. Transition mechanisms enable coexistence.

TCP/IP is the de facto standard for network communication and underpins the global Internet. It supports scalable routing, inter-network communication, and a broad ecosystem of protocols and applications.