When organizing Knowledge articles in Salesforce, Data Categories provide a hierarchical structure to classify and manage content effectively. Each Data Category Group can have up to 10 levels in its hierarchy, allowing for detailed categorization of articles.​

It's important to note the following limits:

Data Category Groups:You can create up to 3 active Data Category Groups.

Categories per Group:Each group can contain up to 100 categories.

Hierarchy Levels:Each group can have a hierarchy depth of up to 10 levels.​

These structures help in filtering and controlling access to Knowledge articles based on user roles and permissions, enhancing the user experience and ensuring relevant content is easily accessible.​