How would HTML code be added to a webpage?

Question

How would one add HTML code snippets into an HTML file without them being rendered as elements on the webpage?

While this could be achieved using images, I'd prefer to have a 'code window with syntax highlighting' like the one pictured below taken from css-tricks.com;

Answer 1

To be able to write html snippets onto an html web page you need to switch opening and closing tags < > with < and >

And to give it syntax highlighting you can use googles own prettify script found Here