How to create a real time web apps for example how to show specific data for specific users.

Question

let's continue above question..| I mean to say that as example of if we create website where you learn code same as solo learn but in website so we have different different users so how we can store data in real time like if user have recently completed full course it will show its progress bar or indicator and now if user logout and when he comes back he will start from where he has lefted that. course.
now this is for one user now second user have completed half of course so for that user we have to show progress bar as per his progress this kind of real time accessibility how it's done in PHP or SQL database?? or JavaScript??

Answer 1

Realtime Web Apps can be greatly done with Node.js.

Answer 2

but for this you must put your site on the server