What does Progressive Enhancement emphasize in web design?

Progressive Enhancement emphasizes a core principle in web design that starts with a solid, basic experience for all users, ensuring that the essential functionality of a website is accessible to everyone, regardless of their browser capabilities or device limitations. This foundational level provides a usable and accessible experience, while enhancements and advanced features are layered on top to cater to users with more capable browsers or devices.

The strength of this approach lies in its focus on accessibility and usability for the widest range of users. For instance, a simple HTML page can provide basic content and functionality, while additional styles, scripts, and features can be added for those whose devices can handle them. This way, users with slower connections or older devices can still access the website's primary functions, while others benefit from a richer experience.

In contrast, emphasizing complex features solely for advanced users would limit the reach and inclusivity of a website. Visually appealing designs are important but do not guarantee usability or functionality. Immediate loading of all resources, regardless of connection quality, can lead to performance issues and negatively impact the user experience, especially for users on slower connections.