A Category is the type of money you have banked and where did it comes from

By choosing the Tenant Who Paid you are specifying where the money came from

If a category you want to enter is not in the field "Category" when you click Choose Category, enter it in the next field “New Category” and continue to enter other fields and submit, this means that next time you come and click the "Category" field the new category you entered will appear in the Category field