Final answer:
The most important point about the service set identifier (SSID) when connecting to a wireless LAN is that clients and access points must have matching SSIDs.
Step-by-step explanation:
When connecting to a wireless local area network (LAN), the most important point about the service set identifier (SSID) is that the clients and all access points (AP) must be configured with matching SSIDs. The SSID is the name of the wireless network and serves as an identifier for devices to connect to the correct network. If the SSID is not the same on all devices within the network, they will not be able to communicate with each other.