TCP (Transmission Control Protocol) is a widely used transport layer protocol that provides reliable, ordered, and error-checked delivery of data between applications running on hosts communicating over an IP network. It is one of the core protocols of the Internet protocol suite and is responsible for providing reliable communication between devices over a network. TCP (Transmission Control Protocol) establishes a virtual connection between two devices before data is transmitted. It ensures that information is delivered without duplication and errors. It also includes flow control and congestion control mechanisms to prevent network congestion.