faizent:
the different is response time.
Local server always has faster response time to local users, of coz.
If you are refering to the availbility of service, then there is no different, as long as the server is up.
btw, is is possible for a website host at both local and US server? or hosted in multiple server around the world? If one of the server down, the website also nvm.

This called cluster?
Guess it is possible for large companies, who can afford having own server at different places. Is it possible that web hosting provider to provide such service?