The Fullscreen API gives you a simple way to make any element on your page fill the entire screen. This is especially useful for images, videos, games, or any content you want users to focus on without distractions. The API works by calling methods directly on DOM elements or the document object.

You use the requestFullscreen method to make an element enter fullscreen mode. This method is available on most HTML elements. When you no longer want fullscreen mode, you call exitFullscreen on the document object to return to normal view. Browsers also provide events to let you know when fullscreen mode changes, which is helpful for updating your UI or handling user actions.