What is the difference between credible and credibility?

Credible - 1.That can be trusted or believed

2.That can be accepted because it seems possible.

- Example : 1. It is just not credible that she would cheat.

2. Community service is seen as the only credible alternative to imprisonment.

Credibility - The quality that someone or somebody has that makes people believe of trust them.

-Example : The prosecution did its best to undermind the credibility of the witness.