TCP stands for Transmission Control Protocol, and it is one of the main protocols used in the internet. TCP provides reliable, ordered, and error-free delivery of data between applications 1. In terms of the OSI model, TCP is a transport-layer protocol. The transport layer is the fourth layer of the OSI model, and it is responsible for establishing end-to-end connections, segmenting data into packets, and ensuring reliable and efficient data transfer 2. The transport layer also provides flow control, congestion control, and error detection and correction mechanisms 2. TCP is not the only transport-layer protocol; another common one is UDP (User Datagram Protocol), which is faster but less reliable than TCP 3. References: 1: TCP/IP TCP, UDP, and IP protocols - IBM 2: Transport Layer | Layer 4 | The OSI-Model 3: TCP/IP Model vs. OSI Model | Similarities and Differences - Fortinet