Dynamics refer to the volume of sound in a musical performance or composition. Dynamics terms are often expressed in Italian and indicate whether the music should be played piano (soft), forte (loud), or somewhere in between. Common dynamics symbols include p for piano, f for forte, pp for pianissimo (very soft), and ff for fortissimo (very loud). Dynamics can also change within a piece through indications like crescendo (gradually getting louder) and decrescendo (gradually getting softer).