The class categories are used to group the classes under one Segment/Category.
For example, Nursery, PP1, PP2 are usually grouped under Pre-Primary Category.
This will help you assign one in-charge or coordinator who looks after this segment to use certain features like handling concerns, generating reports.
Class categories are used in the learning-based assessment which is designed specially for Montessori curriculum based schools.
During admissions, you can set the application number format for each category of classes.
Path: Settings/Organisation/Manage Organisation/ Classes