Evernote supports two fields for organization of note data; Notebooks and Tags (both are fields in the note metadata)
There is no support for Folders.
You seem to be comparing use of the Notebook field to the Tag field
You didn't mention the important Notebook function of identifying notes as
- online/local (Windows/Mac)
- offline (IOS/Android)
Also note the maximum number of tags is 100,000
The maximum for notebooks is 250; 1,000 for paid accounts.