The Category List allows you to manage your Article Channels. You can publish, edit and change the display order quite easily.
If you want to apply an action such as publishing or unpublishing a Category, check its box on the left and choose the action from the drop down at the top of the page. You can apply actions to multiple Categories at a time.
To edit the Display Order of the Categories, edit the display order values on the screen and click the <Save Display Order> button.
To add new categories, click the <+ Category> button. This will take you to a screen to add your new category.