Difference between Impregnability and Invulnerability

What is the difference between Impregnability and Invulnerability?

Impregnability as a noun is the quality or state of being impregnable; invincibility. while Invulnerability as a noun is the state of being invulnerable.

We hope you now know whether to use Impregnability or Invulnerability in your sentence.