What is the opposite of the "sub" prefix?

The term subcategories refers to lower level categories.

Which term should I use to refer to higher level categories?

Does supercategories sound right?

Solution 1:

Supercategories is technically correct.

There are also subscript and superscript to back this example.

Solution 2:

For folders the term parent folder is usually used. And since categories are quite similar to folders, you may want to use parent category for higher-level categories. Or you can use upper-level categories.

Solution 3:

Movies often have subtitles, translated texts below the picture. When opera productions project translated texts above the stage, they are called surtitles.

Solution 4:

Well, there is no defined prefix or word to be an opposite of "sub".

However, the higher level for "subcategories" is simply categories and the lower level is sub-subcategories and to go a third level down is sub-sub-subcategories and so on.