The quantity which indicates the state and direction of vibrating body is known as?

The quantity which indicates the state and direction of vibrating body is known as?

Explanation

The quantity that indicates the state and direction of a vibrating body is phase. 

Phase describes the position of a vibrating body in its cycle at a specific point in time.
It essentially tells you where the body is in its back-and-forth motion (or oscillation) relative to its starting point or a reference point.
This includes both the body's position and its direction of movement at that instant.