How to know if listTree must be called for an entity

[breakfree]

We are developing a mobile app for espocrm. I am unable to determine how to load folder structure for example Documents, Products etc. How do I know what entity requires us to present the folder tree? I found the listTree call so that I know how to use. But I need to know what entity I should make the listTree call. I could not find it in Meta. Any other place I need to look. Could you please point me in the right direction?