  In this article, we review the basic concepts of quantum radars as such types
of the devices while highlighting differences with their classical analogs. We
discuss how several concepts from traditional radars technology, e.g., target
detection sensitivity, noise resilience and ranging accuracy can be translated
to quantum radars. We examine such new far-field sensing protocols as quantum
illumination (QI), and engineering opportunities enabled by its different
realizations. We consider possibilities of achieving super-sensitivity and
super-resolution using quantum correlations, and discuss possibilities to
create quantum correlated states in practice.
