  With the advent of device independent quantum information processing,
nonlocality is nowadays regarded as a resource to implement various tasks. On
the analogy of entanglement theory we approach nonlocality from this
perspective. In order to do so, we analyze in full detail the operations that
can be implemented in this scenario and under which nonlocality cannot
increase. This provides a theoretical ground to study how to order and quantify
nonlocal behaviours. Finally, we review several nonlocality measures and
discuss their validity from this point of view.
