How does an oscilloscope measure frequency and voltage?

I’d like to have a brief description of how an oscilloscope can measure voltage and frequency.

How would you describe this in a language that shows that you understand a bit more than just the basics?

I mean, not in an “Albert Einstein” way of explaining it, but also not in a 5th grade way.

I hope I made myself clear enough. If not, please say so.

Thanks in advance!