A network link that only connects two points, for instance a serial (PPP) connection is PointToPoint.

Ethernet is not a PointToPoint network as it can support multiple connections and you can talk to anyone on the Ethernet (even if you have to go via a switch or a hub).

PointToPoint connections are interesting because usually one or the other or both ends don't have distinct IP addresses since it's implicit who you are sending to (the other end of the link -- duh!).