Gatsby is an open-source framework designed for building fast, secure, and modern websites and applications. It operates on the Jamstack architecture, leveraging React, GraphQL, and a rich plugin ecosystem to create high-performance, dynamically generated web experiences. Gatsby enables developers to pull data from various sources and seamlessly integrate it into static sites, providing a responsive and optimized frontend. The platform also offers hosting services, robust documentation, and a range of tools to enhance development workflows.