Failure
Loss of ability to operate to specification, or exactly within limits. A failure may effect a Configuration Item (CI) or an IT Service.
Impact
Failure is inevitable in complex systems. The impact depends entirely on the system's resilience and the organization's response.
Weinto take
We celebrate failure (in non-production environments). We use Chaos Engineering to intentionally inject failure into our systems to verify that they recover automatically. If you can't survive a server failure at 2 PM on a Tuesday, you won't survive it at 3 AM on a Saturday.