How to show relation data?

So, I have 3 collection types. STORES, PRODUCTS and CATEGORIES.

Stores has many categories.
Categories has many products.
Products has one category.

So what I wanna do is: When I get the data of the store, the categories are returned, but without the products. It is returning only the name, the id, and all the information about the category itself but not the products.

How can I show the products as well when I get the store data?

Solution: Populate!