HR 8799 is a planetary system with several planets, planetesimal belts, and dust. We made a coherent analysis of various observational data for all known components of the system. Our results pose new constraints on the age of the system, masses and orbits of the planets, as well as the location and masses of the dust belts. Despite some apparent similarities with the Solar system, a close inspection uncovers significant differences between the two systems. They reveal different architecture, have likely formed in different ways, and probably follow different evolutionary paths.