Heraldry is a language with a fixed grammar, and the grammar is the point: a shield divided, charged with an ordinary, and blazoned in a precise order that has been more or less unchanged since the thirteenth century. Read a blazon once and you can read any other one ever written.
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There are only six tinctures and two classes of them. The metals — gold and silver — and the colours — red, blue, green, black and purple. The rule of tincture says a metal must not be placed on a metal nor a colour on a colour, and it exists because a charge has to be visible against its field, and because in the original context — a banner in a battle — a yellow charge on a red field simply disappeared.
And the blazon is always in the same order: field, ordinary, charge. Never charge first, never ordinary before the field. Read it that way and any blazon in English can be parsed.
Heraldry is one of the few medieval systems that never went out of use. It is still in force at the College of Arms in London, it is still used for the coats of arms of the United Kingdom's own departments, and it is still a working international language with its own rules for the treatment of foreign augmentations and differences — the small symbols added to a family's arms to show which son had which.
That is remarkable for a device invented to identify people who were wearing armour at a tournament, and it survives because the system is genuinely efficient: a shield is a field of colour, a few strong shapes, and a strict order of description.