There is a fact in Software Testing which says :
Testing is used to find errors in the Software but cannot be used to show the correctness of Software . I am unable to get the significance of the Word Correctness here . Also is it true that Correctness is impossible to achieve in a Software ?
Since sufficiently complex software may have an infinite number of possible bugs, it is logically impossible to show the correctness of software by testing.
Absence of revealed errors (bugs) doesn't imply absence of all errors.