HTML stands for HyperText Markup Language. It is a markup language to design or structure a web page. Every single website in the world is designed with HTML.
We can also say it is an HTML document, basically web browsers are used to see the HTML document. When we open any website to our web browser it loads an HTML document from the server of that website and then shows it in the web browser.
HTML documents are structured with HTML tags or HTML elements. In the post, the structure of an HTML tag you will understand how an element or tags are created for the HTML document.