How does microsoftonline.com know which device I am on, and whether it is a registered device?

Most of the webprogramming and IT security I know is from ten years ago. I’m far from being a pro, so please keep my ignorance in mind when answering.
Back then, browsers sometimes sent details about the client in the headers. Eg browser v… Continue reading How does microsoftonline.com know which device I am on, and whether it is a registered device?