An HTML element is a type of HTML (HyperText Markup Language) document component, one of several types of HTML nodes (there are also text nodes, comment nodes and others). The first used version of HTML was written by Tim Berners-Lee in 1993 and there have since been many versions of HTML. The most commonly used version is HTML 4.01, which became official standard in December 1999. An HTML document is composed of a tree of simple HTML nodes, such as text nodes, and HTML elements, which add semantics and formatting to parts of document (e.g., make text bold, organize it into paragraphs, lists and tables, or embed hyperlinks and images). Each element can have HTML attributes specified. Elements can also have content, including other elements and text. As is generally understood, the position of an element is indicated as spanning from a start tag and is terminated by an end tag. This is the case for many, but not all, elements within an HTML document. The distinction is explicitly emphasised in HTML 4.01 Specification: Elements are not tags. Some people refer to elements as tags (e.g., "the P tag"). Remember that the element is one thing, and the tag (be it start or end tag) is another. For instance, the HEAD element is always present, even though both start and end HEAD tags may be missing in the markup. Similarly the W3C Recommendation HTML 5.1 2nd Edition explicitly says: Tags are used to delimit the start and end of elements in the markup. (...) The start and end tags of certain normal elements can be omitted, (...) The contents of the element must be placed between just after the start tag (which might be implied, in certain cases) and just before the end tag (which again, might be implied, in certain cases). and: Certain tags can be omitted. NOTE: Omitting an element's start tag (...) does not mean the element is not present; it is implied, but it is still there. For example, an HTML document always has a root element, even if the string doesn't appear anywhere in the markup.