Graceful downgrade and progressive enhancement

These two concepts are popular with CSS3,

Progressive enhancement: Build the page for the lower version first to ensure the most basic functionality. Then optimize for a high-level version to improve the user experience.

Graceful downgrade: Build the full functionality from the beginning and then be compatible with the low-version browser.

Go

The "Graceful downgrade" view

The "Graceful downgrade" view is that the site should be designed for the most advanced and sophisticated browsers. Test work in browsers that are considered "obsolete" or functionally missing is scheduled in the final stages of the development cycle, and the test object is limited to the previous version of the main browser (IE, Mozilla, etc.).

In this design paradigm, older browsers are thought to offer only a "poor, but passable" browsing experience. You can make small adjustments to fit a particular browser. But since they are not the focus of our attention, other differences will be ignored in addition to fixing larger errors.

"Progressive enhancement" view

The "progressive enhancement" view is that the focus should be on the content itself.

Content is the incentive for us to build our website. Some sites show it, some collect it, some seek, some operate, and some websites even contain all the above, but the same point is that they all involve content. This makes "progressive enhancement" a more reasonable design paradigm. That's why it was immediately adopted by Yahoo! and used to build its "tiered browser support (graded Browser)" strategy.

Graceful downgrade and progressive enhancement