P versus NP
Concept
The most famous unsolved problem in computer science, questioning if problems whose solutions can be quickly verified can also be quickly solved.
Mentioned in 2 videos
Videos Mentioning P versus NP

Juergen Schmidhuber: Godel Machines, Meta-Learning, and LSTMs | Lex Fridman Podcast #11
Lex Fridman
A major theoretical problem in computer science concerning the relationship between two complexity classes: problems that can be quickly solved (P) and problems whose solutions can be quickly verified (NP). Schmidhuber finds it theoretically interesting and a source of intuition.

The greatest unsolved problem in computer science...
Fireship
The most famous unsolved problem in computer science, questioning if problems whose solutions can be quickly verified can also be quickly solved.