In a score, this symbol tells the performer to take a breath (or make a slight pause for non-wind instruments). This pause usually does not affect the overall tempo. For bowed instruments, it indicates to lift the bow and play the next note with a downward (or upward, if marked) bow.
Indicates a brief, silent pause, during which time is not counted. In ensemble playing, time resumes when the conductor or leader indicates. For piano this usually means that the player should release all keys and pedals.