Learn in the textbookNetwork Classification and the Physical Foundation of Wired Connections
DefinitionA network interface card (ネットワークインタフェースカード, NIC) is the part that connects a device such as a PC or printer to a LAN so it can communicate.
ExplanationIt has a socket (port) for the cable and passes signals between the device and the network. It is also called a LAN adapter, and most current PCs have one built in from the start. Every NIC is assigned a unique number for identifying the device, its MAC address (MACアドレス), at the time of manufacture.
AnalogyIt is like the front door of a house. It is the entrance between the street and the inside, and people and parcels come and go through it.
Memory hookThe abbreviation NIC is pronounced "nick". Interface means a boundary or point of contact, so think of it as the part sitting where the device meets the network.