Help:Create a category
General
A category is a grouping of articles. Simple as that.
By using categories you get an index page for that category, and also a reference to the category-page at the bottom of each article in that category.
Create a Category
To make an article memeber of a category, you simply put the following tag somewhere on the page: [[Category:CategoryName]] where CategoryName is the name of the category (duh!).
You don't need to actually create the category - just mark one page as a member of a category and it exists!
For example, to make an article member of the Forest category, you put the following line somewhere in the page:
[[Category:Forest]]
Please note that the markup looks like an ordinary inta-wiki link, but in this special case it won't act like one.
Link to the category
If you want to make a link to the category-page, you put a colon in front of the name: [[:Category:Forest]] --> Category:Forest.
Edit the category page
The category page is actually an article itself. It will always display a list of articles, but if you edit the page you can add info in the area above the articles.