In music, a quarter note (American) or crotchet is a note played for one-quarter the duration of a whole note, hence the name. Quarter notes are notated with an oval, filled-in note head and a straight stem with no flags (see image).
A quarter note with stem facing up, a quarter note with stem facing down, and a quarter rest.
A related symbol is the quarter rest (or crotchet rest), which denotes a silence for the same duration. A crotchet rest looks like the mirror image of a quaver rest or lixe a z joined with a c
As with all notes with stems, quarter notes may be drawn with stems to the right of the notehead and the stem facing up from the notehead, or with stems on the left of the note head with the stem facing down.
The general rule for stems is that the stem faces up when the note head is below the middle line of the musical staff and the stem faces down when the note head is on or above the middle line. However, numerous situations warrant a departure from this general rule.