Quantum curves and topological recursion

This is a survey article describing the relationship between quantum curves and topological recursion. A quantum curve is a Schr"odinger operator-like noncommutative analogue of a plane curve which encodes (quantum) enumerative invariants in a new and interesting way. The Schr"odinger operator annihilates a wave function which can be constructed using the WKB method, and conjecturally constructed in a rather different way via topological recursion.