What is Service Worker?
The background script owning cache and update lifecycle. Versioned caches with explicit update prompts beat silent staleness every time.
Related terms
PWA Manifest & Icons
The metadata making a site installable: name, icons, theme color, display mode. Manifest plus service worker turns a website into an app-like install.
Offline Fallback & App Shell
A cached shell that renders when the network fails. Offline capability is a reliability feature users notice exactly when they need it most.
Install Prompt
The add-to-home-screen moment, shown when engagement signals say yes — not on first paint. Timing the prompt is the difference between installs and dismissals.
Svelte Runes
The `$state`, `$derived`, `$effect`, and `$props` primitives powering Svelte 5 reactivity. Runes are mandatory in generated code: explicit, compilable, and consistent across every component.
File-Based Routing
Pages defined by file location: `+page.svelte` renders, `+layout.svelte` wraps, `+server.js` serves data. The route tree is the app map — no separate router config to drift.
Load Function
Server-side data loading for a route before it renders. Load on the server for content crawlers and users need immediately; reach for client fetching only for interactive extras.