What is indicated by the "HTML downloaded" event?

The "HTML downloaded" event signifies that the last byte of the current page has been received. This milestone indicates that the web browser has completed downloading the entire HTML document from the server. At this point, the server has sent all the necessary data needed for the page, allowing the browser to proceed with the next steps in the rendering process, such as parsing the HTML and constructing the Document Object Model (DOM).

Understanding where this event fits within the overall loading and rendering lifecycle of a web page is crucial. Only after this event does the browser have all the information necessary to begin rendering the page visually to the user.

The other options relate to different stages in the document loading lifecycle: the first byte received indicates the request has started, the document ready for parsing occurs when the HTML is being processed, and fully rendered refers to the complete visual display of the page after all content (including images, CSS, and JavaScript) has loaded. Each of these events plays a different role in the browser's handling of web pages, showcasing different checkpoints in the rendering process.