Svelte is a frontend framework that aims to be lean and elegant, similar to React and Vue. It's compiler-based, which means the Svelte compiler turns Svelte code into regular DOM manipulations at build-time, making it small and efficient. Components in Svelte are reusable, self-contained pieces of UI that can manage their own state and receive data from parent components via properties. Props allow passing data from a parent component to a child component, similar to HTML attributes. Svelte uses an {#each} block to loop through arrays of items, and it has built-in state management with stores, which help manage shared state across different components.