Okay kiddo, so you know how sometimes you have things that belong together, like your socks? Well, an associator is like a really smart machine that helps other machines put things that belong together in the right place.
For example, imagine a big warehouse with lots of different things in it, and there are machines moving all those things around. Some machines need certain things to do their jobs, like a machine that makes cookies needs flour and sugar. The associator makes sure that the machines that need flour and sugar get them when they need them.
It's like a really good helper that helps keep things organized and makes sure everything works smoothly. Pretty cool, huh?