Mockups & Prototypes
Mockups are a step up from wireframes. A mockup is a static design representation in which the product's identity is applied through color, typography and visual style.
Prototypes are the interactive versions of wireframes & mockups which can be used to test the actual user journey on your site through clickable links, buttons etc.
Note: You DO NOT need to know coding(HTML & CSS) to build interactive prototypes. The tools like Pencil do that automatically for you as you drag & drop.