It also provides details on how to use a data file in your app, which are summarized in the following steps: This page describes what you can do with data files and lists supported data file formats. Local data files support scenarios where your users never have a network connection. Just as layers in your app can use data sourced from online services, such as ArcGIS Online, WFS, or WMS services, layers can also use data from data files stored locally on your user's device.