SvelteKit is a meta-framework built on top of Svelte, designed to create robust and high-performance web applications. It provides a complete solution for building full-stack web applications, including features like routing, server-side rendering, data fetching, and API endpoints. Think of it as a framework that takes the core Svelte library and adds the necessary structure and tools to build more complex, full-fledged web applications. 

Here's a more detailed explanation:

• Svelte's Foundation:
  SvelteKit leverages the Svelte compiler, which is known for its ability to shift the work to compile time, resulting in efficient runtime performance. 
• Beyond UI:
  While Svelte focuses on building user interfaces, SvelteKit provides the framework for creating full-fledged web applications, including routing, data fetching, and server-side rendering. 
• Routing:
  SvelteKit uses a file-system based routing system, where the structure of your project's files reflects the structure of your application's routes. 
• Server-Side Rendering (SSR):
  SvelteKit allows you to render pages on the server, improving initial page load times and SEO. 
• API Endpoints:
  SvelteKit provides a way to create API endpoints for handling data requests and other server-side logic. 
• Adaptability:
  SvelteKit offers flexibility in deployment, allowing you to choose the best rendering method (server-side, client-side, or hybrid) for different parts of your application. 
• Developer Experience:
  SvelteKit is known for its fast hot reloading during development, making the development process more efficient. 

In essence, SvelteKit takes the reactive nature of Svelte and adds the scaffolding and tools needed to build a complete, production-ready web application. 

This video gives a brief overview of SvelteKit and its core features: