I'm googling and googling again to find where sharepoint store the settings for webparts. Especially where it stores the user settings for one webpart and where it stores the disposition/order of webpart in a page. I found nothing.
Can you point me in the right direction ?
Can this be altered using csom or rest ?
EDIT: I'm not looking how to write a webpart and expose its properties. I want to know where sharepoint stores values of those properties for user X or Y.