A Progressive Web App can be considered as middle ground between a mobile app and a web app. Users access PWA through URL just like they access a regular website, but in case of PWA, user experience is more like a mobile app instead of a web app. Following are a few major features of PWA:
Server Side Rendered (SSR) web apps are best suited for consumer facing websites where SEO and time to content are the most important criteria. Unlike SPA, SSR app make content available in advance to browser/search engine. Fast page load is directly associated with conversion rate.