Web applications can be something as simple as a hook-up to an external data source or something fully responsive like a Progressive Web Application.
A PWA is a hybrid of a mobile application and a traditional website that incorporates the best features of both. It is a website developed using web technologies but offers the convenience of a mobile application including push notifications.
PWAs have been slowly building support over the last several years. Some big name companies have implemented PWAs as part of their distribution strategy or even for strategic functional offerings. We’re talking the likes of Twitter, Starbucks, Google, etc.