What is Astro?

Astro is a modern front-end framework for building fast, optimized web applications. Astro allows you to write components using your favorite JavaScript framework (like React, Vue, or Svelte), or just use HTML and CSS for more straightforward static content. Notably, unlike traditional JavaScript frameworks, Astro does not send any JavaScript to the browser by default. This results in faster load times and improved performance.

Astro also supports partial hydration, a feature that lets you specify which components should be hydrated with JavaScript and which should remain static. This way, you can limit the amount of JavaScript sent to the client, optimizing performance without sacrificing interactivity where it's needed.

It's worth mentioning that the information here is accurate as of September 2021, and there might be changes or improvements in Astro and its build system post this period. Please refer to the latest Astro documentation or community resources for the most accurate and updated information.