In heraldry, the term star may refer to any star-shaped charge with any number of rays, which may appear straight or wavy, and may or may not be pierced. While there has been much confusion between the two due to their similar shape, a star with straight-sided rays is usually called a mullet while one with wavy rays is usually called an estoile.

While a mullet may have any number of points, it is presumed to have five unless otherwise specified in the blazon, and pierced mullets are common; estoiles, however, are presumed to have six rays and (as of 1909) had not been found pierced. In Scottish heraldry, an estoile is the same as in English heraldry, but it has been said that mullet refers only to a mullet pierced (also called a spur revel), while one that is not pierced is called a star.