.jrxml is the report design file, it's format is in human readable XML, it can be complied into a JasperReport object and saved as a .jasper.jasper is the compiled version of the .jrxml and can be loaded directly into a JasperReport object ready to be filled with data.jrprint is the serialized JasperPrint object, a report that have already been filled with data and can be loaded to be printed, viewed and/or exported to desired format..jrpxml is the XML rappresentativo of a JasperPrint object it can be modified and then unmarshaled to retrieve the JasperPrint object