HTML is an abbrevation for Hypertext Markup Language. HTML-documents consist of text, text awards and further brands or markings. That's what is called tags in HTML. These tags are so to speak the constituents for a Website. They give the order, what your brwoser shall show. Tags are included by pointed brackets in HTML, for example: <html>.
You surely have noticed, that there's mostly a "couple of tags" like <html> ... </html>. This simply only serves for the delimitation, so that the browser interprets only that, what stands between these both tags.
Here one example of a typical HTML file:
In HTML there is a variety of such tags. We want to introduce only some of them here. We start with the most important one: » HTML.