Question

I am trying to understand facebook like live notifications system to notify users, whenever someone adds them as friend, like their post or posts replies to their comments. This happens as soon as someone hits like button or posts comment in facebook. I was wondering if there is any server side or scripting can be done so that whenever there is new notification entry in my database table,
kindly suggest how it works in facebook.

Answer 1

It’s done using push events: http://en.wikipedia.org/wiki/Push_technology