Wordpress - The loop - With categories instead of posts

There are the loop and WP Query object. They are helpful to loop out posts and pages.

Category loop

I have 1500 categories and in the future there might be 15000 posts. Each category is important which is why I want to loop them out, like the loop (like it does with single posts).

I can't really figure it out. I came across get_categori开发者_如何学Ces but it does not support paging.