Okay kiddo, do you remember playing with those foam puzzle mats that clicked together? Reticulated foam is kind of like that, but it's made in a different way.
So, regular foam has a lot of tiny little closed off bubbles inside of it that hold air. But reticulated foam is made by cutting open those bubbles, so that they all connect with each other and make a lot of little holes.
These holes make the foam super breathable, which means that it can be used in things like air filters or in padding for athletes, because it helps to keep sweat and moisture from getting trapped. Reticulated foam also tends to be a bit more durable than regular foam, which means that it lasts longer and can handle getting squished and moved around without breaking down as easily.
Overall, reticulated foam is just a fancier type of foam that's really good at letting air move through it and that can hold up to a lot of wear and tear.