You’ve probably seen many references to HTML5, along with mentions of certain features being “Deprecated” or “New” in HTML5. This can sometimes be confusing, as you find out that the way you thought you were “supposed” to do something is now not the right way at all.
It can also be annoying — especially since most of these “deprecated features” still work on most browsers. Why bother learning a new way of doing something if the old way works just fine?
And, of course, it can be difficult to find the right information sometimes. Content on the internet doesn’t live forever… but almost. And the older content is, the more likely it is that you’ll find it on a search engine. (All things being equal, Google and the others prefer older content. Also, older content has had more time to acquire backlinks.) This means that you will often find out-of-date tutorials when you are looking for information about HTML.

You probably already know that HTML, or HyperText Markup Language, is the language used for web documents. It is not a programming language, but rather a language that identifies the meaning, purpose, and structure of text within a document.
You can easily understand the structure of the document because it is simple, and you are an intelligent human being who has read many documents in your life. But your web browser needs to understand the document in order to present it to you in an intelligent and meaningful way.

So we use HTML tags (also called “elements”) to identify the different pieces of the document.
For this simple document, we can add an <h1> tag to identify the main heading for the page (the title of the document), and </h1> to close it. Use the <h2> tag to identify the first headline within the content, and a </h2> tag to identify the block of content following it as a paragraph.