In music, dynamics refers to the volume of the music. Dynamics can be gradual changes, sharp changes or stable volume levels. Within a piece, dynamics rarely stay static and change regularly to emphasize particular notes or sections.
Gradual changes in volume are crescendo for growing louder and decrescendo or diminuedo for growing softer. These gradual shifts are often used over a few bars to create a climactic moment or dramatic tension within the piece.
Sharp, sudden changes in volume come in a couple of different types. Fortepiano is a note that is very loud when hit, but then diminishes immediately. Sometimes, this is followed by a crescendo for a more dramatic effect and sound. Sforzando is a sudden accent that stands out from the dynamic markings around it.
The dynamic markings that represent a stable volume for the marked parts are made of "p" for pianio, "m" for moderate and "f" for forte. Multiple "p" markings, such as "pp" or "ppp" stand for gradually softer volume, adding an "issi" to the word with each added letter. For example, "ppp" is "pianississimo." Similarly, multiple "f" markings stand for increasing volume. The "ff" marking is "fortissimo," and so on. The "mp" and "mf" markings are the middle of the road dynamic marks, standing for "mezzopiano" and "mezzoforte" respectively.