Preact is a declarative UI library and a lightweight alternative to React for building user interfaces. It utilizes a component-based architecture and a virtual DOM to sync application state to the browser interface efficiently.
The framework implements a modern React API and provides a compatibility layer to ensure existing component libraries and patterns can run within its environment. It also functions as a server-side rendering engine, generating HTML on the server and hydrating it on the client to optimize page load speeds.
Additional capabilities include virtual DOM state management to reduce expensive rendering operations and a pluggable rendering scheduler to manage the timing of user interface updates.
