IP is a datagram based technology. DIFFERENCE BETWEEN PACKETS AND DATAGRAM
As specified at: http://en.wikipedia.org/wiki/Packet_(information_technology)
In general, the term packet applies to any message formatted as a packet, while the term datagram is generally reserved for packets of an “unreliable” service.
A “reliable” service is one that notifies the user if delivery fails, while an “unreliable” one does not notify the user if delivery fails. For example, IP provides an unreliable service.
Together, TCP and IP provide a reliable service, whereas UDP and IP provide an unreliable one. All these protocols use packets, but UDP packets are generally called datagrams.
If a network does not guarantee packet delivery, then it becomes the host’s responsibility to provide reliability by detecting and retransmitting lost packets. Subsequent experience on the ARPANET indicated that the network itself could not reliably detect all packet delivery failures, and this pushed responsibility for error detection onto the sending host in any case. This led to the development of the end-to-end principle, which is one of the Internet’s fundamental design assumptions.
The following answers are incorrect: IP segment. Is incorrect because IP segment is a detractor, the correct terminology is TCP segment. IP is a datagram based technology. IP frame. Is incorrect because IP frame is a detractor, the correct terminology is Ethernet frame. IP is a datagram based technology.
IP fragment. Is incorrect because IP fragment is a detractor.
References: Wikipedia http://en.wikipedia.org/wiki/Internet_Protocol