Typekit is a subscription-based service that provides access to a vast library of fonts for web and desktop use. It allows designers and developers to easily incorporate high-quality typography into their projects without the need for manual font file management. By using Typekit, users can sync fonts across different devices and platforms, ensuring consistency in design. The service integrates seamlessly with popular design tools and web development frameworks, making it a valuable resource for creating visually appealing websites and applications.