This document discusses progressive web apps (PWAs). It notes that PWAs aim to make web apps feel like native mobile apps by being discoverable, installable, linkable, safe, responsive and progressive. The document outlines some key characteristics of PWAs, including that they need to be served from secure origins and have app manifests. It also discusses some common misconceptions around PWAs and notes that as PWAs improve, they will continue to blur the line between web apps and native mobile apps.