To communicate without wire, computers and end devices require a wireless network interface card (WNIC). A wireless network interface card (WNIC) is a network card which connects to a wireless radio-based network. It is just like other NICs, functioning on the Layer 1 and Layer 2 of the OSI Model. It performs the same operation as a normal network card, except instead of operating through network cables, it operates wirelessly. The card contains an antenna to send and receive microwave signals.
Laptops, tablets, smartphones now all include built-in wireless NICs. However, if a device does not have a built-in wireless NIC, then we can use a USB wireless adapter.
If we need a wireless network interface card (WNIC) in a desktop computer, we can install the WNIC in the PCI bus. The card is also available in the shape of USB and PC card. The figure below illustrates both USB WNIC and WNIC for PC’s expansion slot.