In one sentence, a graphic guide is the bible of a brand image*.
Otherwise, if we try to develop further, we can say that it is a printed or Web document that brings together the components of a brand image and the guidelines necessary for the reproduction/declination of this visual identity.
At Bras Gauche, we use the term graphic guide, but you may have already heard of standards book, graphic standards, graphic charter, brand book…
They all have the same function, only different names. At the agency, we prefer to speak of a guide because these are not regulations, laws or orders. We want it to be a tool to help you work with your logo and branding.