What do nanometers (nm) refer to when talking about microprocessors? Why is smaller better?

Question

I often hear about a new, smaller microprocessor that is, for example 5nm instead of 7nm.

In: Engineering

Answer 1

A huge amount of time is wasted when you need billions of calculations to travel aross a 10nm distance compared to a 7nm distance. Getting processors to be smaller means less time is wasted on travel, more processors can fit in the same area, and heat becomes more concentrated which (when cooled properly) will be an advantage over spreading that heat over other modules of the processor that run more efficiently when cool.