Category "doctype"

What happens if I don't put a <!DOCTYPE html> in my code? Will it make any major changes?

I'm working on several projects with HTML, and sometimes I forget to put <!DOCTYPE html>. Will it make any big or noticeable changes?

<meta charset="utf-8"> vs <meta http-equiv="Content-Type">

In order to define charset for HTML5 Doctype, which notation should I use? Short: <meta charset="utf-8" /> Long: <meta http-equiv="Content-Type" c