Okay kiddo, imagine you're walking down the street and you see a big sign that has something written or a picture on it, it's called an advertising column. It's like a giant page of a book, but outside on the street for everyone to see. Companies use advertising columns to tell people about their products or services, and they hope that people will see it and want to buy what they are selling.
Sometimes these advertising columns are tall and skinny like a column, and sometimes they are bigger and take up the whole side of a building. They might have pictures of food, clothes, toys, or even movies. They want you to see it and remember it later so you might buy it or tell your friends about it.
Just like how you like to show off your cool new toy or shirt to your friends, companies want to show off their products too. And they do that by using advertising columns.