What is the difference between a wireless home router and an enterprise wireless access point, and what is a wireless NIC?

A home wireless router combines three functions (AP + switch + router) in one device. An enterprise AP is a dedicated wireless access point, often managed by a WLC. A wireless NIC is the client-side adapter that connects to the AP.

Wireless home router (3-in-1):

• Access Point: Provides wireless connectivity (802.11)
• Switch: Interconnects wired devices (usually 4 Ethernet ports)
• Router: Provides default gateway, NAT, and internet connectivity

Enterprise AP:

• Dedicated single-function device — only provides wireless access
• Connected to the wired network via Ethernet (often with PoE)
• Managed centrally by a WLC in enterprise deployments

Wireless NIC (client adapter):

• Built into most modern devices (laptops, phones, tablets)
• USB wireless adapters available for devices without integrated wireless
• Contains a wireless transmitter/receiver
• Must support the same 802.11 standard as the AP to communicate

Go deeper:

• Wireless access point (Wikipedia) — the AP as a base station bridging Wi-Fi clients to the wired network.
• Wireless LAN (Wikipedia) — stations with wireless NICs and the AP-centric infrastructure mode.