This section describes how to use communication styles that don't use
connections (styles SOCK_DGRAM and SOCK_RDM). Using
these styles, you group data into packets and each packet is an
independent communication. You specify the destination for each
packet individually.
Datagram packets are like letters: you send each one independently
with its own destination address, and they may arrive in the wrong
order or not at all.
The listen and accept functions are not allowed for
sockets using connectionless communication styles.
