All data files are placed in a directory next to your installer that has the name of your installer with the extension .dat. For example, if your media file name is hello_4_0 (resulting in a Windows installer executable hello_4_0.exe), the directory containing the external data files is named hello_4_0.dat. You have to ship this directory in the same relative location on your CD or DVD.
The number of data files depends the definition of your installation components. The data files are generated in such a way that
If components do not overlap, there's a one-to-one correspondence between data files and installation components.
Data files are generated just like for the "External" mode, but only for installation components that have been marked as downloadable in the installation component definition. If no installation components are marked as "downloadable", this mode will behave like the "Included in media file" mode. For a "net installer", all installation components are "downloadable".
For this mode, you have to enter a HTTP download URL, so the installer knows from where it should download the data files at runtime if the user requests downloadable components. The URL must begin with http:// or https:// and point to a directory where you place the data files. For example, if the data file hello_windows_4_0.000 is downloadable and the download URL is https://www.test.com/components, the data file must be uploaded to the web server, so that the installer can download the data file from the URL https://www.test.com/components/hello_windows_4_0.000.
Any data files that you leave in the data file directory next to the installer will not be downloaded. This means that if you test your installer directory from the location where it was generated, the installer finds all data files in the data file directory and does not try to download them.