The NIC or Network Interface Card is designed to allow your computer to have communications with other computers. Who they talk to is determined by the protocol drivers that you have selected. By default windows installs Microsoft Client for networks, this will allow windows systems to talk to each other as well as to share files and printers.
The most commonly used protocol is Internet Protocol [TCP/IP] this will allow you to talk to any number of computer systems including those on the Internet. TCP/IP is supported on every computer platform as well as many pieces of electonic devices.
A few years back the Apple computer could only talk to other computers that were running the AppleTalk protocol, there were drivers available for your PC so that you could talk to these systems, Apple soon discovered that they were much better off creating a TCP/IP stack (program) for their operating system so that their computers could talk to just about everything else on the network.
Your NIC card is useless with out a driver and the best driver to have installed is TCP/IP but you can install other drivers as well.
The interface card for each computer is similar in structure although its shape may be different. Just like all humans are same in structure but different in appearance. This fact has a remarkable implication on the way two computers can communicate with each other. Each interface card has a pair of pins for transmission, we call it Tx+ and Tx-, and similarly we have a pair for reception Rx+ and Rx-.