The Pacman Conjecture is based on an imaginary character called Pacman who eats dots in a video game. Pacman travels around a two-dimensional world that is created by a shape called a polygon. A polygon is like a shape made from straight lines that closes up at the end, like a square or a triangle.
The Pacman Conjecture says that if you draw a bunch of lines inside a polygon so that the lines start and end at the corners of the polygon and each line is unique (doesn't cross any other lines), then you can always create a path for Pacman to travel along that passes through all the corners of the polygon exactly once, and doesn't cross any of the lines.
In simpler terms, the Pacman Conjecture means that if you draw a bunch of lines inside a shape, you can always find a way to walk around the shape and visit every corner of it without crossing any of the lines. Think of it like a treasure hunt or a maze, where you have to find a path that takes you to all the important places without getting lost or stuck.
Mathematicians have been trying to prove the Pacman Conjecture for many years, but it hasn't been solved yet. It's a bit like a mystery that people are still trying to solve, by thinking very carefully about how shapes and lines work together. If someone does solve the Pacman Conjecture, it will be a very big achievement and will help us understand more about geometry and math!