This tutorial outlines the process of implementing localization in a Svelte application, enabling the app to support multiple languages with the default language being detected by the browser. The guide begins with setting up a new Svelte project using a template, followed by creating locale dictionaries for English, Spanish, and French. It then introduces the installation of necessary packages like svelte-i18n for managing locales and svelte-routing for enabling a routing mechanism across multiple pages. The tutorial further explains how to configure these packages, create a layout to display the localized content, and provide users the ability to switch languages via a dropdown menu. It highlights Svelte's advantages such as reactivity and lightweight performance, which allow for faster content display by handling tasks during the compiling step rather than in the browser. The tutorial concludes with styling the application using CSS, ensuring a visually appealing and responsive UI, and suggests potential expansions like adding more pages, backend functionality, or private routes for a more comprehensive user experience.