What Is an SSID, or Service Set Identifier?

You’ll often see the acronym “SSID” when Wi-Fi networks are involved. A Wi-Fi network’s SSID is the technical term for its network name. For example, if you see a sign telling you to join a network with an SSID of “Airport WiFi”, you just need to pull up the list of wireless networks nearby and join the “Airport WiFi” network.
by Chris Hoffman via How-To Geek