What's the difference between streams and datagrams in network programming?

Question

What\'s the difference between sockets (stream) vs sockets (datagrams)? Why use one over the other?

Answer 1

If it is the network programming I think starting from sockets would be a good start.
socket = ip + port
there are three types of sockets
stream (TCP, order and delivery guaranteed,no duplication,no length or char boundaries for data,connection-oriented,reliable, concurrency)
datagram(UDP,packet-based, connectionless, datagram size limit, data can be lost or duplicated, order not guaranteed,not reliable)
raw (direct access to lower layer protocols IP,ICMP)
I do not see any strict rule for transport protocol type as to what socket has to use what transport protocol and reliability should not be mistaken because UDP is realiable in case both ends are active.
Reliability refers to more like reliability of delivery since there are sequence number checks by using TCP as transport protocol which do not exist in UDP.It is better using network protocol analyzer like wireshark tcpdump etc to see what your software is exactly doing; kind of verification or merging theory on the paper with your work in action.