SSID 
service set identifier 
Every wireless network or network subset (such as a BSS, zn ESS, or an IBSS) has a unique identifier called an SSID (and may be called a BSSID, an ESSID, and so on, depending on what it is identifying). Every device connected to that part of the network uses the same SSID to identify itself as part of the family, so to speak, when it wants to gain access to the network or verify the origin of a data packet it's sending over the network. Using SSID carries some security risk, however, because it can be detected by wardrivers and used to gain unauthorized access. Some network administrators, therefore, disable SSID.