  In the last years the possibility of creating and manipulating quantum states
of light has paved the way to the development of new technologies exploiting
peculiar properties of quantum states, as quantum information, quantum
metrology & sensing, quantum imaging ...
  In particular Quantum Imaging addresses the possibility of overcoming limits
of classical optics by using quantum resources as entanglement or
sub-poissonian statistics. Albeit quantum imaging is a more recent field than
other quantum technologies, e.g. quantum information, it is now substantially
mature for application. Several different protocols have been proposed, some of
them only theoretically, others with an experimental implementation and a few
of them pointing to a clear application. Here we present a few of the most
mature protocols ranging from ghost imaging to sub shot noise imaging and sub
Rayleigh imaging.
