A quarter note with stem facing up, a quarter note with stem facing down, and a quarter rest.
A crotchet or quarter note is a note played for one fourth of a whole note (or semibreve). Quarter notes are written as a filled-in oval (or round) note head and a straight, flagless stem (the line). The stem usually points up (like a d) if it is below the middle line of the stave or down (like a p) if it is on or above the middle line.