Gatsby is JS framework for building fast sites and apps

Gatsby is a popular open-source JavaScript framework for building blazing-fast websites and applications. It is based on React and GraphQL, and it provides a set of features and optimizations that make it easy to create high-performance web experiences.

Here are some key features of Gatsby:

1. Static Site Generation (SSG): Gatsby generates static HTML pages at build-time, which can be served from a CDN for fast performance. This enables faster page loads, improved SEO, and reduced server load.
2. React-based: Gatsby is built on top of React, one of the most popular JavaScript libraries for building user interfaces. This makes it easy for React developers to get started with Gatsby and leverage their existing knowledge of React.
3. GraphQL for Data Fetching: Gatsby uses GraphQL, a powerful and flexible query language for APIs, to fetch data from various sources like APIs, databases, and markdown files. This allows developers to easily source data and create dynamic content for their websites.
4. Plugin System: Gatsby has a rich ecosystem of plugins that provide a wide range of functionalities, such as image optimization, CMS integrations, SEO, and more. This makes it easy to extend the functionality of Gatsby sites and customize them to specific needs.
5. Developer Experience: Gatsby provides a set of developer-friendly features, such as hot module replacement (HMR) for fast development iteration, a built-in development server with features like error overlays, and a comprehensive error reporting system.
6. Theming and Styling: Gatsby has built-in support for theming and styling with popular CSS-in-JS libraries like styled-components, emotion, and others. This makes it easy to create and manage styles for components in a modular and scalable way.
7. Image Optimization: Gatsby has built-in support for image optimization, including automatic resizing, lazy loading, and responsive images. This helps improve website performance by optimizing images for different devices and network conditions.
8. SEO and Performance Optimizations: Gatsby includes a set of built-in optimizations for SEO and performance, such as automatic generation of optimized HTML, CSS, and JavaScript, automatic prefetching of critical assets, and more.
9. Contentful Editing: Gatsby provides integration with Contentful, a popular headless CMS, for content editing and management. This allows content creators to easily update and publish content on Gatsby websites without requiring code changes.
10. Extensibility: Gatsby is highly extensible and allows developers to add custom configurations, plugins, and themes to suit the needs of their specific project.

Gatsby is widely used by developers and organizations to create high-performance websites, blogs, documentation sites, and web applications. Its focus on performance, developer experience, and flexibility makes it a popular choice for building modern web experiences.