React promises to programmers a model in which subcomponents cannot directly affect enclosing components ("data flows down"); efficient updating of the HTML document when data changes; and a clean separation between components on a modern single-page application.
Ruby on Rails, often called RoR or simply Rails, it's an open source framework for web applications written in Ruby
Ruby is a dynamic, reflective, object-oriented, general-purpose programming language
Django it's an open source framework for web applications development, written in Python
Python is a widely used general-purpose, high-level programming language