Radio-loud active galactic nuclei (RL AGN) are the most powerful stationary cosmic engines radiating through the universe. The intrinsic properties deduced from thermal emission, high resolution radio imaging and very high energy observations, are continuously improving a global AGN classification scheme. We know for the last decades that their spectral energy distribution from radio to gamma-ray is linked to the kpc scale morphology of their radio jets, as well as their accretion disk regime.
However, numerous unexplained behaviours detected from their variabilities, apparent motions in jets, and non-standard spectral energy distributions are still strongly challenging our deep understanding of their nature.
I will present how the recent link observed between the pc scale radio structure of jets and different spectral classes allow us to propose an interpretation of these observations.
Following an innovative view of multiple recollimation shocks in radially stratified jets, I will show the last developments of the evolving paradigm of radio-loud AGN structures.