Active galactic nuclei (AGN) with jets are the most energetic stationary systems in the universe, shining in all wavelengths from radio to very-high-energy gamma rays (E>100 GeV).
Jetted AGN were historically classified from their optical features and large scale radio jet morphology without a clear link between the sources due to the great variety of their observed relativistic beaming. In the early 90's the general unification of jetted AGN was set, presenting a clear dichotomy between low power sources known as "BL Lac objects" and high power ones known as "Flat spectrum radio quasars" (FSRQs). However, the progress made in this last decade with intensive observing multiwavelength campaigns, and better sensitivities in all the electromagnetic spectrum, increasingly highlight sources with complex behaviours not fitting into the usual classification.
I will show how the parsec-scale imaging from radio very-long-baseline-interferometry (VLBI) observations coupled to broadband spectral models and hydrodynamic jet simulations lead us toward an updated unification scheme of the jetted AGN phenomenon.