CryLib.Network is a collection of classes used to communicate over the network with some classes providing more aid and some only basic functionality.
E.g. CryLib.Network.Protocols.CommonProtocolBase provides functionality to connect and listen for clients with different network protocol versions provided by the assembly. Meaning, a client only capable of using protocol version 1 can connect with a server using mainly the version 3, but internaly converting the connection for better compatibility and still provide new features if possible.
On the other hand, there are classes like CryLib.Network.SimpleNetworking which provide functions for sending and receiving data but not initiating the connection or maintaining it.
Furthermore, CryLib.Network.Server provides a class that can listen and connect clients sending requests and waiting for the requests return. Multiple requests can be made without waiting for an answer.