Equivalence partitioning is a technique of black-box testing (testing without knowledge of the internal workings of a system, machine, etc) to assay the functionality of a system based on predefined outcomes. The concept of equivalence stems from the fact that the test inputs are divided on partitioned into valid and invalid inputs sets that are considered to be equivalent and made to undergo the same procedure. Inputs which are representative of the different partitions or divisions are then selected and fed into the system. Thus, equivalence partitioning is a quick method of system (or software) testing which can be applied at all levels.
