The P tag is used to indicate paragraphs.
Some browsers render extra whitespace when multiple empty paragraphs are used in sequence.
This is not required by the specs, so do not count on this to get vertical whitespace in your document. In the very first version of HTML, the P tag was an empty tag like BR . Some references and books still claim that this is the case. However, HTML 2.0 defines the P tag as a container, and there is no difference between a paragraph with and one without explicit alignment.