What part of BLE is GATT concerned with?

Answer

GATT, the generic attribute profile is concerned with exchanging data within a connection using attributes grouped into characteristics and services with a GATT server. GATT defines the following roles: GATT Server - typically has data GATT Client - typically wants data Note that GATT is independent of the roles defined by GAP, and a GATT server or client can exist on a GAP central role device, a GAP peripheral role device, or both. GATT clients will read or write to the GATT server using the attribute protocol (ATT) as a transport.