Smart Client Applications have all the richness of the windows User Interface, with all the flexibility of a web site.

How do they do this?

Well, a smart client application is a windows based application that uses web protocols to communicate back to a shared database. Due to this it can have an extended degree of separation from the database and still function like it was in the same room as the database.

A good example of this is the latest version of outlook (2003) supports this, and can communicate to an exchange server securely (using HTTPS) from across the internet and have similar performance as if they were in the same office.