You can look for differences between any two selected items in the scene. These items can be files, layers, instances, groups, or just geometry.
You can also use this feature to investigate the differences between two versions of the same model.
During the comparison, Autodesk Navisworks starts at the level of each item, and recursively travels down each path on the Selection Tree, comparing each item it comes across in terms of the criteria you requested.
When the comparison is finished, the results can be highlighted in the Scene View. The following color-coding is used by default:
You can save the comparison results as selection sets with automatic comments describing the found differences in more detail.