The trend started with Hotmail, then Gmail and Yahoo followed it. You enter only email address first, then press Next button and a new form appears for the password.
Previously, there was a single form with email and password fields and a sign in or log in button. Facebook still goes this way.
Main question:
- Why are they doing this?
Bonus Questions:
- Is there a particular terminology for this kind of behavior?
- Is there a special feature in Javascript/HTML that easily enables such forms?
