The 'Categories' area is where you will create and/or modify the categories and subcategories for your site. You can create as many categories and subcategories as you need. If you have more than a few categories and subcategories to create, it may help to write them out first to determine the best structure.
When you click on the 'Categories' link, a page loads that lists your current categories and subcategories in the left column of the table. The top categories will be left justified with their subcategories listed underneath. Subcategories will have two greater-than symbols (">>") indicating that they are a "child" of their "parent" category. Keep in mind that subcategories can also have subcategories placed in them. These will be designated with a second pair of greater-than symbols (">>"). For each level down in the category structure, another pair of greater-than symbols (">>") will appear next to the name designating their place in the category hierarchy.
Beside each category it shows three icons. These are for edit, duplicate, and delete.
Reordering your Categories
By default categories sort alphabetical then by weight. If you would like a category to appear first then you would change it's weight to a higher amount. The higher the weight the more it goes to the top.
Note: the code only looks at the value of the number in relationship to other numbers of that same level (and parent category if it's a subcategory).