A content library is not a single file; it is a collection of many files that are stored in a single folder.
At the time you create a new content library, AutoCAD Mechanical toolset prompts you to specify the folder in which to create the content library. Once the content library is ready for publishing, you must distribute the entire folder. Once you copy this folder to another computer, you must add the library to Content Manager.
Sometimes, copying content libraries to multiple computers is tedious. Instead of copying the folder, you can share the folder on a network drive. Once shared, in the Content Manager you point to the network location.
If many computers access the shared content libraries, pointing to the shared location from each computer can be tedious. In such a case you can distribute a file that is known as the Path Information File. The Path Information File stores the path to all content libraries. Hence, all you have to do is set up 1 computer and copy its Path Information File to other computers. After that you display the Content Manager and load the new Path Information file to it.
You can include the Path Information File while creating a network deployment of AutoCAD Mechanical toolset. Hence, when you distribute AutoCAD Mechanical toolset, the Path Information File automatically points the installation to the shared content libraries.