Datagram When data are being transferred over a network they are divided into neat packets of a suitable size. This is a convenient way for the network to handle the transfers. A packet of data, a datagram, is made up of two parts: a header part and a data part. The header part contains information about the sender and how to reach the receiver, as well as information about the type of data that will follow in the data part. The header part furthermore tells the receiving computer how to put the packets of data back together again into something meaningful. Depending on the capacity of the network, datagrams can themselves be split into further fragments. However, the exact way in which datagrams are constructed also depends on the protocol used for the particular data transfer.
