When you write a new post/page in Wordpress, you have the option to put that post/page in an Existing or New category. Does that answer your question?
Log-in to Wordpress and go to Manage >> Categories and at the bottom of the categories page there will be a section with the title "Add New Category". Let's say that we're going to add the category named "Digital Point Forums". Category Name: Digital Point Forums Category Slug: digital-point-forums (if you don't create this, it will create it for you automatically) Category Parent: If you want this category to be within another category, then chose which category you want it to be in from the list. If you want it to be a parent category, choose "None". Description: Most themes don't show the description if you list your categories, but some may. So you may want to make this user friendly or leave it blank.