All the block element areas are surrounded by different properties. Some we can see, such as background-colors and borders. Some are not visible, such as padding and margins. The default amount of space the padding and margin take up is set by each browser. There are different amounts for each one. Just as we can add a background color or a border, we can also use CSS to define the width and height of the padding and margins. By defining these styles, we control or create our page layouts.
All these tags have no CSS styling. On this page, they might look one way on one browser, and differently on another. Although we can see the spaces between each one, you cannot tell exactly where one element ends and the next begins.