Kerio Connect supports note folders. This implies that note folders are stores on the server and you can access them also via Kerio WebMail.
These folders work the same as the other supported folder types:
note folders are stored on the server in the folder tree,
public note folders can be created,
note folders can be shared with other users and it is also possible to set access rights for other users.
To learn what note folders are used for as well as how to handle them, refer to MS Outlook user guides.