Only in very simple circuits are they the same. OV and OC limits normally apply to power supplies. So a typical PC Mother board will need 5V with a current up to 3.5A. The problem is that the integrated circuits will malfunction and over heat at a voltage of 5.25V, so the power supply might have its over voltage trip set to 5.1V. The over current trip could be set to 4 or 5A, because when the current gets this high the damage has been done, all the current trip is doing is to stop the power supply overheating and damaging its self as well.
If you are dealing with some unknown circuit, the current trip could be set as low as possible, say 10mA, this is so there is not enough current for the circuit to get damaged. Under these circumstances, the voltage might only be 2V but it could be enough to examine the circuit to see how it works.
Frank