Action Engineering : 3D Digital Transformation You Trust
Each instantiation of a component is called an instance. It may appear that the part model (component) is copied several times within a single assembly, yet the other representations are merely visualizations of the source data.
Alternate Definitions:

PTC - An instance of an object, is the same as an exact duplicate of the object. An instance is really an object that shares the exact same properties as the original. It will always stay the same as the original regardless of what changes are made to the original.