  Einstein-Podolsky-Rosen steering is a form of inseparability in quantum
theory commonly acknowledged to be intermediate between entanglement and Bell
nonlocality. However, this statement has so far only been proven for a
restricted class of measurements, namely projective measurements. Here we prove
that entanglement, one-way steering, two-way steering and nonlocality are
genuinely different considering general measurements, i.e. single round
positive-operator-valued-measures. Finally, we show that the use of sequences
of measurements is relevant for steering tests, as they can be used to reveal
"hidden steering".
