n.
In marketing and advertising, a device placed on or before a premises to identify its occupant and the nature of the business done there or, placed at a distance, to advertise a business or its products.
The ancient Egyptians and Greeks used signs for advertising purposes, as did the Romans, who also, in effect, created signboards by whitewashing convenient sections of walls for suitable inscriptions. Early shop signs were developed when tradesmen, dealing with a largely illiterate public, devised certain easily recognizable emblems to represent their trades. Modern sign designers use various forms of animation and light.