MS SQL Server Report Builder versus Power BI Report Builder

Hi all,

Does any one of you can explain me the difference between the traditional ssrs report builder vs the power bi report builder.

I understood power bi report builder is to created paginated reports which is nothing but .rdl report.

But what makes these two different and which should i prefer when i intend to publish report to both on-permise report server as well as to the power bi service(cloud)

Thanks in advance.