Relationships are not physical objects in themselves but a defined link between objects. In the simplest case a relationship calculates the distance between two related entities and re-calculates this distance whenever either of the related items are moved. This linking process is quite efficient and can be expanded to include many points and many objects simultaneously. By building a relationship you can use this dynamic link in many powerful ways.
Reporting. Relationships can be used for automatically updating dynamic changes between objects. Relationships can therefore be used directly to report deviations.
Build Operations. Relationships can be used to update displays or watch windows to guide users to specific location for part alignment.
Dynamic Geometry Fitting. Geometry Relationships are a special type of relationship that updates the properties of an object based upon the measurements. The relationship links the measurements to the resulting geometry making it dynamic.
Alignment. Multiple Relationships can be used simultaneously and weighted independently for sophisticated alignment operations