Mockups refer to static representations of a product that are often used in work environments. They cannot be interacted with. In essence, they show what the final product will be like.
Mockups serve as visual drafts of an application or web page. The goal is to bring a concept or a wireframe to life and to allow designers to see how various visual elements can work in harmony with one another. Using mockups gives stakeholders in the page the opportunity to preview what the page will look like and make suggestions for changes in aspects such as color, layout, images, styles, etc. You can check out what a page would look like if it were filled with a secondary color by making a second version of your mockup. In the same way, if you wish to make a change, like inserting a header while repositioning a picture, your mockup can help show the team how the potential change might look.