Vue.js is a progressive framework for building user interfaces that focuses solely on the view layer. It was created by Evan You and takes inspiration from other frameworks to combine useful ideas in an approachable way. Vue can be installed via CDN, NPM, or Vue CLI. It uses components to organize code for reusability. Components can also accept external data via props. Additional tools like Vuex, Vue Router, and libraries help with state management, routing, and following best practices.