Some basic concepts
NDIS Interface: Network Driver Specification Interface, wraps NIC drivers and allow communication with multiple protocols, binds a NIC to a protocol.
Streams: multiple channels allowing broader bandwidth for data transfer, envelop the protocols.
Transport Driver Interface: allows software drivers (server, redirector, etc) to communicate with protocols.
Redirectors: software in WS that redirect network drives, printers requests to network I/O requests.
Servers: software that allows a device to accept requests from other devices.