Okay kiddo, you know how when you want to tell someone how to draw something or build something, you can't always just use words? Sometimes you need pictures to show them what you mean.
Well, engineers have a way of making those pictures that they use to show how to build things. These pictures are called engineering drawings, and they help everyone who's working on a big project to understand what they should be doing.
Now, engineers all over the world use the same symbols on their engineering drawings to make sure everyone knows what they're talking about. And these symbols are like a special language that only engineers can understand (just like how your friends might have secret codes or hand signals that only they understand).
For example, there's a symbol that looks like a circle with an X through it. Engineers use this symbol to show where they want a hole to be drilled. They might write a number next to the symbol to show how big the hole should be.
There's also a symbol that looks like a triangle with one side missing. This symbol is used to show where something is going to be welded. Engineers might write a letter next to this symbol to show what kind of welding needs to be done.
And there are many more symbols like these that engineers use to show important information on their engineering drawings. By using the same symbols all over the world, engineers can work together and understand each other even if they don't speak the same language.