What role does TCP play in TCP/IP?

TCP, or Transmission Control Protocol, is a key component of the TCP/IP model that specifically focuses on facilitating reliable communication between hosts on a network. This protocol is essential for ensuring that data being transferred over the internet reaches its destination safely and in the correct order.

One of the primary roles of TCP is to establish a connection between hosts before data can be exchanged. This connection-oriented approach involves a three-way handshake process, which helps to confirm that both sender and receiver are ready for data transmission. By creating a reliable channel, TCP can manage data segments, ensure they are received correctly, and handle retransmissions in case of lost packets, thus providing a robust environment for applications that require high reliability, such as web browsing, email, and file transfers.

The other options reflect functions that are not accurate for TCP. For instance, managing physical network connections is typically the role of lower layers in the OSI model, such as the physical and data link layers. Handling data encryption involves different protocols specialized for securing data, such as SSL/TLS. While TCP is involved in the transmission of data packets, it does more than just facilitate their movement; it provides essential control for data integrity and order, which is critical for effective communication.