GraphQL is a data query language and runtime designed and used at Facebook to request and deliver data to mobile and web apps. wikipedia.org

C# (pronounced see sharp) is a multi-paradigm programming language encompassing strong typing, imperative, declarative, functional, generic, object-oriented (class-based), and component-oriented programming disciplines. wikipedia.org

"TypeScript is a free and open source programming language developed and maintained by Microsoft. It is a strict superset of JavaScript, and adds optional static typing and class-based object-oriented programming to the language. Anders Hejlsberg, lead architect of C# and creator of Delphi and Turbo Pascal, has worked on the development of TypeScript." wikipedia.org

JavaScript is a prototype-based scripting language that is dynamic, weakly typed and has first-class functions. It is a multi-paradigm language, supporting object-oriented, imperative, and functional programming styles. wikipedia.org

Node.js is a software system designed for writing highly-scalable internet applications, notably web servers. Programs are written in JavaScript, using event-driven, asynchronous I/O to minimize overhead and maximize scalability. wikipedia.org

OAuth (Open Authorization) is an open standard for authorization. It allows users to share their private resources (e.g., photos, videos, contact lists) stored on one site with another site without having to hand out their credentials, typically username and password.