ELI5: Explain Like I'm 5

Bekenstein bound

The Bekenstein Bound is like a rule that tells us how much information one thing can store. Basically, you can think of it like a box - the Bekenstein Bound tells us how small the box can be and still fit all the information inside it. So if the box is too small, there won't be enough room for all the information. It was proposed by an astronomer named Jacob Bekenstein.