Hector,

N-Tier is a high level system architecture. It specifies that specific tiers will be responsible for specific behaviors. If you violate that design then you no longer have N-Tier and you loose the benefits it provides.

In VFP adn N-Tier presentation tier has no data environment, it gets all of teh data from the Business logic tier. The presentation tier NEVER touches data directly.

The business tier calls the data tier for data, it NEVER touchs the data directly either. It is exaclty this clear seperation of responsibilities that allows N-Tier system to scale easily.