LabVIEW Project Library
A LabVIEW Project Library is a file with extension, *.lvlib. It is an XML file that stores information about the files owned by the library. The Project Explorer is used to view and edit these files. It is not recommended to edit the XML directly.
A LabVIEW Project Library is different than the LabVIEW Library that has the extension, *.llb. LabVIEW Libraries are single files on disk that contain other files in it; whereas the LabVIEW Project Library does not contain the files it owns. Its files exist separately on disk.
LabVIEW Project Libraries can hold other LabVIEW Project Libraries, LabVIEW Classes, LabVIEW StateChart Libraries, and XControls. When other Libraries are added to a LabVIEW Project Library, only the Library file itself is referenced in the LabVIEW Project Library file. This is helpful because adding to or modifying a Library won't necessitate a change to the LabVIEW Project Library file and wouldn't require the file to be updated in Source Code Control.