Okay kiddo, so when we're on a boat and we want to sail, we need to think about which direction the wind is blowing. You can feel the wind by putting your hand outside the car window, right? It's the same thing with a boat.
When we're sailing into the wind, we say that we're "going upwind" or "sailing close-hauled". This is like trying to walk straight into a strong wind - it's really hard! The boat has to zigzag back and forth, going a little bit sideways with each turn, to make any progress at all.
When the wind is coming from the side of the boat, we call this a "beam reach". This is like walking forward when the wind is at your side. It's much easier than going into the wind, and the boat can go straight ahead without zigzagging.
When the wind is coming from behind the boat, we call this a "downwind" or "running" position. This is like walking with the wind pushing you from behind - it's pretty easy, but sometimes you have to be careful not to trip!
There are two other positions that are in between these three - "broad reach" and "close reach". These are the positions that the boat is in when the wind is coming from somewhere in between straight ahead or straight behind.
So that's what we mean when we talk about the "point of sail" on a boat - it's all about which way the wind is blowing and how the boat is positioned in relation to it.