Vue.js is a progressive JavaScript framework designed for building user interfaces. It's approachable, performant, and versatile. Vue builds on standard HTML, CSS, and JavaScript, offering an intuitive API and comprehensive documentation. Its reactive rendering system is compiler-optimized, minimizing the need for manual tuning. The framework's ecosystem is incrementally adoptable, allowing it to scale from a lightweight library to a full-featured framework. Official libraries like Vue Router and Pinia, along with extensive tooling and community resources, support development across various scales.