A rhythm section (also called a backup band) is a group of musicians within a music ensemble or band who provide the underlying rhythm and pulse of the accompaniment, providing a rhythmic reference and beat for the rest of the band.
Your Samsung Galaxy S3 android phone has water damage indicators to tell whether your phone was in contact with water or any liquid. It is difficult to find these indicators as they are different for each carrier. If your android phone was dropped in water, You can try to repair your water damaged android phone.
As you described, there are two water damage indicators, one on the battery and the other one in the battery compartment: There might be other ways to tell if the device was exposed to water though, like the moisture under back cover or condensation under inside the screen. Dmitriy.