When you create an application on Qlik Sense Desktop, Qlik Sense creates a file on the machine with .qvf extension. QVF is a file format used by Qlik Sense to store the visualization and the base data which is used for visualization. The QVF format stores the data in compressed format. The compression depends on the numbers of unique values available in the final data.

QVF can be used for two purposes: first, to load the data from the data source using the relevant connection string and storing data in QVD, and secondly you can use the QVF for developing the data model (logical linking between data) and create a visualization on top of that.