Note 1 to entry: White-box testing aims to achieve a defined level of coverage of the internal structure of the item under test and to correct any faults that are revealed. The technique is normally applied to software but the same approach can be used for hardware.

Note 2 to entry: Software coverage may be measured at various levels, e.g., by the proportion of statements, branches, or paths through the code that have been executed.

Note 3 to entry: White-box testing is usually employed at lower levels of software testing such as for unit or integration test.