What is the difference between processor (CPU) and microprocessor?

Question

what is the difference between "processor (CPU)" and "microprocessor" in the sense of computer architecture? These terms confuse me.

Answer 1

The difference is purely historical. In the old days of lore, the CPU used to sit in a separate enclosure, like here:

A microprocessor is a particular implementation of processor which happens to fit in a single electronic component (chip) package:

Clearly, nowadays all processors are microprocessors, so the distinction is completely blurred.