Answer :

The visible page content on an HTML document is defined by the tag. Here's a breakdown to explain why:

1. The tag in HTML represents the content of an HTML document. It contains all the content that you want to display on a web page, such as text, images, videos, links, and more.

2. When you open an HTML document, the tag is where you put all the visible elements that users will see when they visit your website. This tag acts as a container for all the content that appears on the webpage.

3. Without the tag, your webpage would be empty because it is where you place everything visible to the user, like text, headings, images, buttons, etc.

Therefore, the tag plays a crucial role in defining the visible page content on an HTML document by encapsulating all the elements that users interact with when they visit a webpage.