With multipoint you can connect your Blue BYRD (2nd generation) to two playback devices at the same time, i.e. to a smartphone and a computer. This way, you can use the earphones on both devices and you won't miss a phone call while working and streaming music.
Multipoint may no be confused with the number of devices the Blue BYRD (2nd generation) can have in its list of paired devices, which is eight.
(Depending on the connected device Multipoint can have limitations.)