eli5 if my monitor is 1080p why does 4k look better than 1080p videos?

Question

shouldn’t 1080p and 4k have no difference if my monitor is only capable of displaying 1080p

In: 422

Answer 1

Beside the resolution difference, 4K & 8k each use a higher bit depth for colour reproduction. This allows them to display more colours and appears more vibrant.

Jumping from 8 to 10 bit colour increases the variety of colours/shades from 16 million to over a billion and the jump from 10 to 12 bit again increases them from a little over a billion to 68 billion.