  We describe the emission properties of blazars, i.e. the AGNs that, due to
their peculiar orientation w.r.t. the observer, allow the most penetrating and
direct view of their central engine. After showing that the extragalactic
GeV-TeV sky is dominated by blazars of various types, we discuss the kind of
blazars that are likely to be jointly detected by AGILE and MAGIC.

Astrophysics