Builders are like builders of big puzzles! They have a special piece of paper called a 'plan.' This plan is made by smart people called engineers. It tells the builders what the building will look like, sort of like a picture.
On the plan, there are special drawings that show where the big doors and small windows will go. It also tells them what materials to use, like wood or bricks, kind of like choosing the right toys to build with!
So, when builders want to make a building, they look at the plan to know exactly what to do, just like following directions in a game!