I learnt a new thing.

What is OpenID
OpenID is a new concept which lets a person to maintain his identity same over the internet. With OpenID a person doesnot need to register in each and every sites in the net. He/she just need to register to a OpenID provider. OpenID works in many sites that support OpenID. This concept is very easy and simple.

How does OpenID works ?
OpendID works in a simple way. First a person needs to register to a OpenID provider of his/her choice or even he/she can maintain one for himself/herself. When you need to visit a site that support OpenID but you are not a member to it then you dont need to register to it. Just provide your OpenID. Then the site takes all the necessary information from the OpenID provider and you can login. Dont need to register to different sites and not to worry about different usernames in different sites.
For more detail see the video.