How does file-based routing work in SvelteKit?

SvelteKit uses a file-system based router in the src/routes/ directory. Each route is a directory containing special files. +page.svelte: the page component (rendered as HTML). +page.js/+page.server.js: data loading functions. +layout.svelte: shared layout for all pages in this directory and subdirectories. +server.js: API endpoint (GET/POST/etc. handlers). Route examples: src/routes/+page.svelte → /. src/routes/about/+page.svelte → /about. src/routes/blog/[slug]/+page.svelte → /blog/:slug. src/routes/(app)/dashboard/+page.svelte → /dashboard (parentheses create route groups that don't affect the URL). Optional segments: [[optional]]. Rest parameters: [...path]. This convention eliminates boilerplate router configuration.