explanation of/for

[Tedwonny]

These two sentences are from the Cambridge Online dictionary:

Could you give me a quick explanation of how it works?
What was her explanation for why she was late?


I am not quite sure how to distinguish between the use of 'of' and 'for'.
I tried asking different questions to see if the answers are different, say, what is the explanation? [ans = how it works, why she was late]; what is the explanation about? [ans also = how it works and why she was late]

So, much obliged if you can show me the differences between the two.

very many thanks!

 

[White Hat]

Could you give me a quick explanation of how it works? We're referring here to a step-by-step instruction on how to use a certain device.

What was her explanation for why she was late? We're just trying to explain why she's behaving that way or did it. (she's not a device - she's a human being whose conduct may be acceptable or reprehensible)

 

[Tedwonny]

So, explanation + of ==> always step-by-step explanation
explanation + for ==> different aspects rather than step-by-step?