ELI5: Explain Like I'm 5

Billboard

A billboard is a really big sign that you see when you're driving or walking outside. It's usually next to a road or on the side of a building. Sometimes a company or group will put a picture of their product or a message they want people to see on the billboard so that lots of people will see it when they're passing by. Think of it as a big poster that everyone can see, even if they're far away!