A Network Interface Card (NIC) or a LAN adapter provides the physical means for a host device to connect to a network.
The same function would be covered for a networking device by a physical port, which can connect the network device to a host device or another network device.
An Interface in most of the cases when we talk about networking and networking devices, we will be referring to a specialized port in an inter-networking device that connects to individual networks. For example for routers that inter connect networks, the ports on them are called network interfaces.
The most commonly used technology when dealing with a LAN, is Ethernet. But do not think this is the only one. We also have other protocols that can govern network communication like Token Ring or FDDI and others, some of them will be mentioned in later articles, but they are less used.
You also must keep in mind that in a network, for example, all computer network interface cards and device interfaces if any other present (like router and switch interfaces that belong to the same network) work using the same set of rules. As a conclusion, you should have the same protocol, else you risk things from complete failure to incompatibility which can lead to other faulty working environments like lack of optimal speed, packet drops and many more.