React Native enables building applications with JavaScript and React targeting different platforms by using native UI building blocks. It was written by Facebook, released in 2015 as open-source software, and is community driven. Major companies like Facebook, Instagram, Tesla, Uber and Wix use React Native. React Native uses the same fundamental UI building blocks as traditional mobile development (e.g. FrameLayout, TextView, ImageView on Android), but instead of writing native code, you write JavaScript and React code. This architecture allows sharing code across platforms while retaining native speeds through the React Native bridge.