User Preset Folder

It totally is! The structure you see here is just referencing folders on your hard drive. 

• The animation presets that are installed with After Effects are in the Presets folder located in the Program Files\Adobe\Adobe After Effects CC\Support Files (Windows) or Applications/Adobe After Effects CC (Mac OS) folder.
• Animation presets that you create are saved by default in the Presets folder located in
  My Documents\Adobe\After Effects CC (Windows) or Documents/Adobe/After Effects CC (Mac OS
  
  The user presets folder (second bullet point) is the intended location for presets you create, but if desired, you can create your own folders in AE's Presets folder, and they'll show up alongside everything else.