To most people, the word 'logo' has very modern associations. It makes us think of things like the golden arches, or the word 'Coca-Cola' in a florid script, or a chrome apple with a concentric bite taken out of it. An image, perhaps even just a shape, that is indelibly associated with a product, a brand or an idea.
However, while the word 'logo' itself was probably first used in that way in roughly the 1930s, the idea of a logo is considerably older. Seals, heralds, crests, sigils and more – all these things have been used throughout history, and all of them have contributed to the ways that logos are understood, used and (sometimes) abused today.
