Datagram
A datagram is an independent, self-contained message sent over the network whose arrival, arrival time, and content are not guaranteed.
Datagram vs. packet?
- Packet is a more generic term. Packets can be retransmitted, whereas a datagram is a data units in connectionless protocols like UDP or in network-layer protocols like IP.
Datagram vs. frame?
A datagram is a self-contained packet of data at L3. A frame is a data packet that includes control information needed for data transmission at the Data Link Layer..