Apache is a free and open-source cross-platform web server software.
Open Graph is a protocol that is used to integrate any web page into the social graph.
PHP is a general-purpose scripting language used for web development.
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.
RequireJS is a JavaScript library and file loader which manages the dependencies between JavaScript files and in modular programming.
YouTube is a video sharing service where users can create their own profile, upload videos, watch, like and comment on other videos.