What are "reasons" and "excuse"? Are they the same thing?

"The main function of a reason is not to justify, but to explain. Reason implies that fault is sincerely recognized and accepted…. that you step up and take accountability for your actions. An excuse exists to justify, blame or defend a fault…with the intent to absolve oneself of accountability."

Google.com

How it normally goes is if someone with authority does something wrong, there are reasons for that.

But if a pleb does something wrong, anything reason they may have is an excuse.

I think an excuse is like a reason but also an attempt to let you off the hook.

Whereas when you have your reasons, you accept the responsibility.

To me, an excuse is an attempt to duck responsibility for whatever happened....i think objectively they are interchangeable but it carries that connotation

Please excuse me for not attending yesterday's class for I had an urgent doc appointment.

Above usage is self explanatory.