What does crescendo mean in music terms?

Crescendo ("to grow" or "increase") is a musical term and notation that indicates a gradual increase in volume to the sound of a piece of music. It is generally used to build tension or excitement in a piece of music and is denoted with an upward line from a soft low pitch to a louder, higher pitch.

Crescendo can also mean a gradual increase in intensity, loudness, or speed of a musical passage, such as a note, chord, phrase, or section. Composers often use it to create a sense of drama or excitement in their music.

The opposite of crescendo is diminuendo, which means to gradually decrease in volume.