The reason the tag appears to cover the entire screen, even though it is a block-level element, is due to the default behavior of the browser's rendering engine. While block-level elements typically expand to fill the width of their parent container, the height of the tag is determined by its content. However, the tag can stretch to fill the entire viewport if there's not enough content to naturally fill the page. This happens because browsers often render the element to take up the full screen by default. When you apply a background color to the , it spans the entire height of the viewport, even if the content doesn’t fill the page, because the background color is applied to the area occupied by the body tag. To prevent this behavior and make the tag behave more like a typical block-level element, you would need to explicitly define the height of both the and tags, often setting them to 100%, which constrains the body to the height of its content rather than filling the entire screen.