Indicator diagram

An indicator diagram is like a picture that shows how an engine is working. Think of it like a map that helps you understand how a car or a train is running. The diagram shows things like how much the engine is pushing out air, how much pressure is inside the engine, and how fast the engine is moving. By looking at the diagram, you can tell if the engine is working well or if it needs some fixing. It's kind of like looking at a picture book with all the different parts of the engine laid out so you can understand how they are working together.