ELI5: Explain Like I'm 5

Reaction–diffusion system

A reaction–diffusion system is like when two things together cause something to happen. Think about mixing paint colors — for example, when you mix red and blue paint, the reaction is that you get the color purple. The same thing happens in reaction-diffusion systems: two different materials can mix together to create something new. It's kind of like a science experiment — you mix different things together and see what you get!