P=>Q is a statement. It says If P is true, then Q is also true.
If you find a case were P is true and Q is false, then the statement P=>Q lied to us which means it is false.
For all the remaining cases of T T , F T , F F , P=>Q isn’t necessarily falsified.
Just think of truth table of implication as a list of all possibilities in the universe of A and B and when do the implication statement fails to satisfy.