In Linux Operating Systems, we have several utilities to connect to specific Wi-Fi Access Point on the basis of SSID (service set identification). If there are several access points with same name we can differentiate with their mac address, which is also called AP’s BSSID (Basic Service Set Identification). In past, we used only BSSID to connect with AP, but now a days we are using ESSID (Extended Service Set Identification) to connect with AP’s. In an ESS, each BSS still has its BSSID, however, the entire ESS uses only one SSID (to facilitate laptop and Mobile Internet Device, MID, mobility and Voice over Wi-Fi, roaming) - now called an ESSID.