Cellular automaton (CA) is like a game or puzzle that can be played on a computer. The game consists of a grid made up of small squares (cells). Each cell can have a certain number of colors and can move around on the grid. When a cell moves, it changes the colors of the cells around it, or it can leave the same color. This can be used to create interesting patterns on the grid. The goal of the game is to create patterns that look cool or solve some type of challenge. It's like a game of chess, where you have to make the right moves to win.