Express is a web application framework for Node.js, released as free and open-source software under the MIT License. It is designed for building web applications and APIs.
Open Graph is a protocol that is used to integrate any web page into the social graph.
Progressive Web Apps (PWAs) are web apps built and enhanced with modern APIs to deliver enhanced capabilities, reliability, and installability while reaching anyone, anywhere, on any device, all with a single codebase.
VK is a Russian online social media and social networking service.