One map file can use multiple sources. For example, you might attach a DWG file to your map file, query in one or two of its layers, and add them as Display Manager layers. Then, you might connect to a SHP file that becomes another layer in your display map, or add features from a geospatial database. The map file remembers all the connections and which objects you’ve added to the map file.
The relationship between the sources and the map file is dynamic. If the data in the source file changes, those changes are updated in your map file. When you change the objects in your map file, you can save those changes back to their original sources.
For drawing objects, you can lock the source drawings so no one else can use them, and you can use save set options to control whether your changes are saved back to the original drawings or affect the current map only.
For geospatial features, you can set an option to save changes to the original source automatically, or you can work offline and update the feature source when you finish editing. Check out a feature to lock it for other users (if the feature source supports this) and check it back in to make it available again.