The mechanism for bringing a whole separate model - another discipline's Revit file, a site survey, a consultant's model - into a project as a live reference, without merging the actual data together. Unlike worksets, which divide ownership within one shared central model, Linked Models are entirely separate files: the architect links the structural engineer's model to coordinate against it, but each team still owns and edits their own file independently.

Getting links positioned correctly depends entirely on shared coordinates being set up right - a link with the wrong coordinate system will look fine in isolation and be meters off once brought into the host model.