A coat of arms is a heraldic visual design on an escutcheon (i.e., shield), surcoat, or tabard (the latter two being outer garments). The coat of arms on an escutcheon forms the central element of the full heraldic achievement, which in its whole consists of a shield, supporters, a crest, and a motto. A coat of arms is traditionally unique to an individual person, family, state, organization, school or corporation. The term itself of 'coat of arms' describing in modern times just the heraldic design, originates from the description of the entire medieval chainmail 'surcoat' garment used in combat or preparation for the latter.
Rolls of arms are collections of many coats of arms, and since the early Modern Age centuries, they have been a source of information for public showing and tracing the membership of a noble family, and therefore its genealogy across time.