Crest 

An addition to the shield in the form of a specific charge placed on a wreath, coronet or chapeau above the helmet of an achievement. Originally the crest was the ornament of the helmet or headpiece, and also afforded protection against a blow. It was originally worn by great men and commanders who placed on the tops of their helmets the figures of animals and other objects, according to their fancies, in order that, looking much taller, they might thereby appear the more formidable to their enemies, and be easily recognised by their own men in the heat and confusion of battle. Even esquires were not allowed the wearing of crests; their helmets were merely decorated with feathers or scrolls, which hanged down upon their armour.

Crests, like arms, were sometimes allusive. Thus, Grey of Wilton used a gray, or badger, and Lord Wells a bucket and chain. In the early days of the crest it was confined to persons of rank, but is now included in every grant of arms.

Sometimes the device used in a crest was also adopted in the badge or cognizance, and vice versa. However the terms are quite distinct from each other, although some ancient authors have been known to use them indiscriminately.