The Transport Layer is the fourth layer in the OSI (Open Systems Interconnection) model, also known as Layer 4. Its primary function is to ensure reliable communication between end devices in a network, coordinating the exchange of data between applications on these devices. The Transport Layer ensures that data arrives in the correct order, corrects errors, removes duplicates, and facilitates efficient and reliable data transfer.
Two well-known protocols at the Transport Layer are the Transmission Control Protocol (TCP) and the User Datagram Protocol (UDP). TCP provides a connection-oriented and reliable communication, while UDP offers connectionless and less reliable communication, preferred in certain use cases where lower latency is more critical than ensuring complete data transmission.
In summary, the Transport Layer is responsible for enabling efficient, reliable, and error-free data transfer between end devices in a network.