HTML

Hypertext Markup Language is the standard language used by browsers to display webpages. HTML was invented by Tim Berners-Lee in 1990, and uses tags. This means that in order to define an element (something like a heading or paragraph), you use a tag - such as <p>, which displays a simple paragraph. Most tags must be closed with closing tags - like </p>, however some elements, like those for images (<img>) and linking external resources (<link>) are auto closing: they don’t need a closing tag. For example, an image is defined as follows:
<img src="image_source_url">
HTML is closely linked with CSS and JavaScript; a comment in HTML is started with <!-- and ended with -->.