Saving an Assembly and Its Components

When you save an assembly, the path and name of each referenced component is saved in the assembly document. when you save or rename a component document, or move it to a different folder.

several ways to save an assembly document.

Save Saves the assembly document, and any referenced component documents that changed.
Save As Saves a copy of the assembly document with a new name or path. After you use Save As, you work in the new assembly document. The original assembly document closes without saving.
Save as copy and continue in the Save As dialog box. Saves a copy of the assembly document, with a new name or path, without replacing the active document. You continue to work in the original assembly document.
Save as copy and open in the Save As dialog box. Saves a copy of the assembly document, with a new name or path, replacing the active document with the copy. The original assembly document remains open.
Save an assembly as a part Saves the assembly as a part. See Save Assembly as Part PropertyManager
With Save As, Save as copy and continue, and Save as copy and open, if any of the components changed since the last Save operation, you receive notification that they must be saved also. If you agree to save them, they are saved in their original referenced locations.