The Document Type Declaration, or DOCTYPE, is the very first thing in an HTML document. It is a preliminary piece of information for web browsers to understand the language in which the web page document has been written. With HTML5, the DOCTYPE declaration is very simple and straightforward.
Here’s how you can use it:
```
```
You just need to write `` at the beginning of your HTML document – before the html tag.
This declaration is not case sensitive, so you can also write it like ``, for example. However, the convention is to use all lowercase letters.
Although HTML5 does not require closing tag, XML syntax demands it, so if you’re using XHTML5, you will have to include the closing tag too.
The DOCTYPE declaration for HTML5 is extremely simple compared to previous versions of HTML where it could be quite long and complicated.
To exemplify it, here is a simple HTML5 document:
```
```
In this example, `` informs the web browser about the document being written in HTML5.
