Description: The Protocol Data Unit (PDU) is a term used to refer to a single unit of information transmitted over a network. In the context of computer networks, a PDU can vary in its form and content depending on the layer of the OSI model it is in. For example, at the application layer, a PDU may be a message, while at the transport layer, it can be considered a segment. At the network layer, it is called a packet, and at the data link layer, it is referred to as a frame. Each PDU includes not only the data being transmitted but also control information, such as source and destination addresses, which are essential for the correct delivery of information. The PDU is fundamental for communication in networks, as it allows for the segmentation of data into manageable units, thus facilitating the process of sending and receiving across different communication protocols. Proper interpretation and handling of PDUs are crucial for the efficient functioning of networks, as each protocol has its own rules and formats for creating and processing these data units.
