TCP

Definitions

1. TCP, or Transmission Control Protocol, is a connection-oriented transport protocol that provides reliable, ordered delivery of data between applications over an IP network. Before any data is sent, TCP establishes a connection using a three-way handshake (SYN, SYN-ACK, ACK), and it guarantees that packets arrive in order, without duplication, and are retransmitted if lost. Flow control and congestion control mechanisms adjust the rate of data transmission based on network conditions, preventing sender overload and network congestion. TCP is the backbone of most internet traffic, underpinning protocols such as HTTP, HTTPS, SMTP, and FTP. It works at Layer 4 of the OSI model and pairs with IP to form the TCP/IP suite. While its reliability features add overhead compared to UDP, TCP is essential for applications where data integrity and order matter, such as web browsing, file transfers, email, and database connections.

   In plain English: The protocol that makes sure data arrives completely and in order over the internet, even if it has to resend lost pieces.

   Example: "Use TCP for the API calls where you need guaranteed delivery, UDP for the real-time game state."

Related Terms

• HTTP
• Rendezvous
• Safety-Critical
• UDP
• RPC
• FTP
• SMTP
• IMAP
• QUIC
• WebRTC
• NAT Traversal
• OSI Model
• TCP/IP
• MTU
• SNI
• Negotiation
• Packet Loss
• Pong