Let's look at some terminology so that we're on the same page:
Wireframe: This is a very basic visual representation of a layout using only outlines, in other words, in black and white. There are no colors, no branding, and no defined styles of any kind.
Design/Comp: This is a fleshed out wireframe with colors, branding, and styles. It's a very close representation (usually, say, 95 percent close to the final product) of the final page/site/app without going into markup or coding of any kind.
HTML mockup or HTML template: This is when the design has been implemented into an actual HTML page with CSS and—sometimes—JavaScript. It can only be viewed in the browser. It's practically an exact representation (99 percent close to the final product) of how the page/site/web app will look and work like.
With the terminology clear, let's continue.
Some professionals, including me, recommend using more modern and efficient...