TCP, or Transmission Control Protocol, is a foundational network protocol that ensures reliable, ordered data delivery between devices. It is widely used for web browsing, email, API requests, and file transfers. TCP establishes a connection before exchanging data, guaranteeing that packets arrive intact and in sequence. Its reliability makes it the default choice for most internet applications. TCP handles retransmissions, congestion control, and flow management automatically. Developers rely on TCP without needing to understand every internal detail.
how it works
TCP uses a three way handshake to establish connections between a client and server. Once connected, it breaks data into packets and numbers them so they can be reassembled correctly. If packets are lost, TCP retransmits them. TCP also adjusts sending speed based on network conditions to avoid congestion. Many protocols, including HTTP, run on top of TCP. Tools like netstat and packet analyzers help developers inspect TCP behavior.