WordPress categories are a very convenient way to organize your posts. You can have parent and child categories making hierarchical arrangement of your posts possible. In addition to that, one post can be into more than one category. This gives you a lot of flexibility to show exactly the posts you want, exactly the way you want them in widgets, menus or directly in your WordPress theme.
1 -) Create Category
Posts > Categories page. You can create or update the category from this page.
2 -) Edit & Customize Category
Posts > Categories page. Click on the category you want to edit. You can update the color, category design styles or other settings from this panel.