Svelte is a modern, open-source web application framework designed to build user interfaces (UIs). It was created by Rich Harris and was first released in 2016. Svelte is unique compared to other popular frameworks like React, Angular, or Vue because it shifts much of the work traditionally done at runtime to build-time, resulting in smaller and more efficient code. Here are some key concepts and features of Svelte: Compiler-based approach: Unlike traditional frameworks, Svelte compiles components into highly efficient JavaScript at build time. This means that the heavy lifting is done during development, and the resulting code sent to the browser is very lightweight. Declarative syntax: Svelte uses a straightforward and declarative syntax, making it easy to learn and use. Components are written using HTML, CSS, and JavaScript, with each component encapsulating its logic and styling. Reactivity: Svelte provides reactive statements and expressions, enabling components to automatically update when their underlying data changes. This reactivity is built into the language itself, so developers don't need to rely on external libraries or hooks. Components: Svelte follows a component-based architecture, where the UI is broken down into reusable and self-contained components. These components can have their own state, methods, and lifecycle hooks. Stores: Svelte has a built-in concept called "stores," which are reactive data containers that allow sharing state between components without passing props explicitly. Stores are useful for managing global or cross-component state. Animations and transitions: Svelte provides built-in support for animations and transitions, making it easier to add smooth and visually appealing effects to your components. Routing: Although Svelte itself doesn't come with a routing solution out of the box, there are third-party libraries available that provide routing capabilities, allowing you to create single-page applications (SPAs). Server-side rendering (SSR): Svelte can be used to implement server-side rendering, which can improve initial load times and SEO. Small bundle size: Since Svelte performs most of the work at build time, the resulting JavaScript bundles are smaller compared to other frameworks, leading to faster loading times for users. Svelte has gained popularity due to its simplicity, efficiency, and fast performance. It's an excellent choice for building modern web applications and is particularly well-suited for projects where small bundle sizes and optimal performance are crucial. However, as with any technology, the choice of framework depends on the specific requirements and preferences of the development team.