A network interface card (NIC) enables a device to connect to and communicate over a network. A wireless access point (WAP) allows wireless devices to join a network and forwards data between them and a wired local area network (LAN).
Functions of Each Device
| Device | Main functions |
|---|---|
| Network interface card | Provides the hardware interface between a device and network; sends and receives data frames; uses a MAC address to identify the interface locally. |
| Wireless access point | Creates Wi-Fi coverage; associates wireless clients; forwards frames between wireless devices and the wired network. |
A NIC may be wired, using an Ethernet cable, or wireless, using radio signals. When transmitting, it converts computer data into signals suitable for the network medium; when receiving, it converts incoming signals into data the computer can process.
A WAP acts primarily as a bridge. For example, a laptop's wireless NIC sends a frame to the WAP, which forwards it to a server on the wired LAN. Returning frames follow the reverse path.
One WAP can serve multiple clients, although capacity and coverage depend on signal strength, interference, bandwidth, physical obstacles, and the number of connected devices.
A common misconception is that a WAP is automatically a router or modem. A standalone WAP provides wireless network access, while a router forwards packets between networks and a modem connects a network to an internet service provider. Consumer equipment often combines these functions.
Exam Technique
For an IB Computer Science A2.1 question, distinguish the devices by function: the NIC connects an individual device to the network, whereas the WAP connects wireless clients to the LAN. If asked to explain rather than identify, describe how a frame is received and forwarded along the path. Use precise terms such as MAC address, frame, wired network, wireless client, router, and modem.