What is a Network Adapter?
A network adapter, also known as Network Interface Card (NIC) is chipset on printed circuit boards that provide physical access from the PC to the LAN or Wi-FI (WLAN) network.
If it is used to provide access to wired LAN then UTP or fiber optic cable is used to connect PC to active network equipment (commonly switch). If it’s used to provide access to wireless network then we basically talk about antenna which is connected to computer via USB or it can be integral part of a motherboard.
The network adapter is responsible for fragmenting the data transmission and formatting the data frames with the necessary header and trailer. A standard IEEE network adapter contains a unique, hard-coded logical address (MAC address), which it includes in the header of each data frame it transmits. The network adapter typically has some amount of buffer memory, which enables it to absorb some number of bits transmitted by the associated device, form the frames, and hold them until such time as the network is available.
In the context of the OSI Reference Model, network adapters function at the Physical and Data Link layers. It also may contain a microprocessor that can relieve the attached device of some routine computational functions.
The network adapter can take a number of forms, including a circuit board that fits into the expansion slot of a desktop PC, a PCMCIA card, or a stand-alone device. Transceivers (transmitter/receivers) are used in LANs to receive a carrier signal and then transmit it on its way. They are embedded in network adapters.
