Hi Alejandro,
Mendix has extensive documentation available to learn more.
See below links:
https://docs.mendix.com/refguide/mapping-documents/
https://docs.mendix.com/refguide/export-mappings/
https://docs.mendix.com/refguide/export-mapping-action/
https://docs.mendix.com/refguide/import-mappings/
https://docs.mendix.com/refguide/import-mapping-action/
In addition to Thomas’ answer, take a look at the Mendix Academy where there are learning paths that go over using import and export mappings in more detail.
The module on Importing And Exporting Your Data looks particularly suitable.
https://academy.mendix.com/link/paths/44/Importing-and-Exporting-Your-Data