Wikipedia
In IEEE 80211 wireless local area networking standards (including Wi-Fi), a service set is a group of wireless network devices which share a service set identifier (SSID)—typically the natural language label that users see as a network name (For example, all of the devices that together form and use a Wi‑Fi network called Foo are a service set) A service set forms a logical network of nodes operating with shared link-layer networking parameters they form one logical network segment A service set is either a basic service set (BSS) or an extended service set (ESS) A basic service set is a subgroup, within a service set, of devices that share physical-layer medium access characteristics (e
Service_set_(802.11_network) - Wikipedia, the free encyclopedia