Resources in Altru can be configured in Tickets - Configuration - Resources.

When you add a new Resource, Category is a required field.
User-added image

While the Category does not appear on a report, it is a filter field on the Resource screen. This is particularly useful since both Group Sales and Facility Rentals use this area. Filtering by Category makes it easier to find different types of Resource. The Resource Category is also a field that appears in Query.

The Category drop-down is a table that you can customize with your own values.