What is "notehead"

In music, a notehead is the elliptical part of a note. Noteheads may be colored completely black or white, indicating the note value (i.e., rhythmic duration). In a whole note, the notehead is the only component of the note. Shorter note values attach a stem to the notehead, and possibly beams or flags. The longer double whole note can be written with vertical lines surrounding it, two attached noteheads, or a rectangular notehead.