Dynamics
Dynamics is referring to the loudness or softness of the music. Dynamics are shown in music through the use of dynamic symbols.
𝆐𝆏
Mezzo Piano
medium quiet
𝆒
Crescendo (cresc.)
gradually louder
𝆓
Decrescendo (decresc.)
or Diminuendo (dim.)
gradually louder
Poco a poco
little by little