Script files are complete blocks of code that are stored in external files such as .qvs or .txt, and they can be included in your application with a single reference. They are conceptually similar to the subroutines that are covered in How to use subroutines in Qlik Sense® recipe in this chapter. However, there is a subtle difference in the usage. QVS simply stands for QlikView Script File.
Everything from data sources, expressions, and visualizations can be governed centrally and the script files can be leveraged in a similar way to help build standards in backend data preparation across multiple applications.