More specifically, an "affiche" is a poster, frequently created by an artist, to advertise an event or the opening of an exhibition. The French verb "afficher" means "to post".
With this information, it is possible to find many examples of French advertisements that could be considered as affiches. Such poster/advertisements are used to attract attention, to draw potential customers or participants in to the event or attraction, to create a market for sales of any items connected with the thing being advertised. The goal of advertising is universal - only the language has changed in your question.
See affiche-francaise.com for many examples of French affiches.