Reflect website changes on all the devices

I made a website having user signup and login , and lets say on my mobile device, It is already logged in , I can see my Profile Info and other stuff, Now I login with my account on desktop, At present both show same information which they should, however, when I update something on my mobile phone,It is reflected in the mobile device only and not in the desktop, for desktop, I need to refresh the page or login again for the changes to take place.

I want that the changes should be reflected on both the devices and any other device too. I am using MySQL Database. Kindly help me out by laying out some sort of steps or wayouts how to achieve the above goal.