This is a description of the category. Categories, unlike tags, can have a hierarchy. You might have a Jazz category, and under that have children categories for Bebop and Big Band. Totally optional.
It look like readable English. Many desktop publishing packages and web page editors now. Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker.
The industry’s standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book.
Dummy text popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.
Various versions have evolved over the years, sometimes by accident, sometimes on purpose. It has survived not only five centuries.