Thread:User talk:Nx/Understanding the function of "categories"

First - please take your time to answer. I know you are working on lots of projects, and this is very low importance and mostly just me not being very skilled at understanding how wiki's work.

I've been playing around in the back of my head about how we navigate around here, and comparing it (i know, i know, bad to compare) with WikiPedia, and i really miss something like wikip's "Portals" that are well laid out, highlights of the best of particular categories, etc.

Our category pages are a start, but i think they could be expanded - however, what I'm not sure is "what is the function of 'category:x' in a wiki. I'm suspect that this is the best approach because i think the way categories work, no matter where on the page you link to it, it would add that page to the "category" in question, correct?   If, for example, I made a "portal page" off of the Christianity category, and linked that to the religion's "portal page", it would add religion to the category, xianity?

I guess I'm asking for a "idiots guide in 100 words or less to what cats are and how they work". Though i have this biting suspicion that making a 'portal page" would be better than modifying the category entry page.