Simpler DOCTYPE declaration
Now in HTML5 you do not have to write a complicated DOCTYPE declarations. DOCTYPEs in older version was complicated and longer because HTML language was SGML based and that's why it required a reference of DTD like <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">. This definitions are sometimes even more complicated because as one had to choose between three different DOCTYPEs possibilities (transitional, strict or frameset).
In HTML5, there is only one way to specify the DOCTYPE <!DOCTYPE html> which means that this page is written in HTML5 as opposed to say HTML 4.01.
Optional "type" attribute
Simpler <meta> tag
Prior to HTML5 we used to write <meta> tag as <meta http-equiv="content-type" content="text/html" charset="utf-8">. In HTML5 you can use simple syntax to specify Character Encoding as <meta charset="utf-8">.
So the Simplified HTML5 document will look like
<link href="main.css" rel="stylesheet" />
Please Like and Share the Blog, if you find it interesting and helpful.