Hey there kiddo,
Have you ever looked at a world map and wondered why it's flat when the world is round? That's because the world is like a ball, and it's really hard to show a ball on a flat piece of paper. But there's a special type of map called a gnomonic projection that tries to show the world as if it was pressed flat onto the paper.
The way it works is like this: imagine you have a big ball, and you stick a flat piece of paper onto it so it touches the ball at one point. Then you shine a light from the center of the ball through the paper, and wherever the light hits the paper, you draw a line. Those lines make up the gnomonic projection.
The cool thing about the gnomonic projection is that it shows distances and directions really accurately. If you wanted to fly from one city to another, you could use a gnomonic projection map to figure out the shortest route.
However, the downside of a gnomonic projection is that it distorts the size and shape of things. Places close to the point where the paper touches the ball look normal, but the farther away you get from that point, the more stretched out things look. So it's not great for seeing what different countries or continents look like compared to each other, but it's really useful for measuring distances and directions.
Hope that helps you understand what a gnomonic projection is all about!