I was wondering what is difference between Jasper reports server and jasper reports IO ? In the official website it indicates that JR-IO has a rest API to generate reports. But as far as I know JR-Server also has a Rest API which has similar functionality. So what's the difference between those two products?
The JasperReports IO is created with scalability in mind from ground up. It is a reporting-only specialized REST API based service.
Just like the JasperReports Library offers reporting functionality to Java applications as a Java API packaged in a JAR file, the JRIO offers the same reporting functionality but in the form of a REST API that can be used to add reporting functionality in service based architectures, regardless of their development/running platform.
JasperReports IO takes care of reporting only and does not have any security of its own and needs to be embedded into parent applications that provide the end user front end. JasperReports IO is not normally used on its own as it does not actually have a UI and needs to be used as a component/service inside some other application.
Actually, in the latest release of JasperReports Server, the report execution can be delegated to a scalable instance of JasperReports IO that runs side-by-side with JRS itself, improving performance and optimizing resource consumption.