Title: What is a hierarchically hyperbolic space?,
Abstract: The first part of this survey is a heuristic, non-technical discussion of
what an HHS is, and the aim is to provide a good mental picture both to those
actively doing research on HHSs and to those who only seek a basic
understanding out of pure curiosity. It can be read independently of the second
part, which is a detailed technical discussion of the axioms and the main tools
to deal with HHSs.