The TCP/IP model defines how devices must transmit data between them and provides communication across networks and long distances. The model represents how data is exchanged and organized over networks. It is divided into four layers that set standards for data exchange and represent how data is processed and packaged in delivery between applications, devices, and servers.
The four layers of the TCP/IP model:
- The data link layer: defines how data is transmitted, handles the physical action of sending and receiving data, and is responsible for transferring data between applications or devices on the network. It involves determining how data should be transmitted by hardware and other transmitting devices on the network, such as a computer device driver, Ethernet cable, network interface card (NIC), or wireless network. It is also called the data link layer, network access layer, network interface layer, or physical layer and is a combination of the physical and data link layers of the OSI network model, which standardizes communication functions in computing and telecommunications systems.
- Internet layer: is responsible for sending packets from the network and managing their movement through the network to ensure they reach their destination. It provides functions and procedures for transmitting data sequences between applications and devices over networks.
- Transport layer: is responsible for ensuring a reliable data connection between the source application or device and its intended destination. This is the layer where data is divided into packets and numbered to create a sequence. The transport layer then determines how much data should be sent, where it should be sent, and at what rate. It ensures that data packets are sent error-free and consistently and receives confirmation that the target device has received the data packets.
- Application layer: refers to programs that need TCP/IP to provide their message. This is the layer that users typically interact with: for example, e-mail systems and messaging platforms. It combines sessions, presentations and applications of the OSI model.