Most websites have a specific layout that is generic across most, if not all, of its pages. This is true for responsive and non-responsive websites. Usually, a website has a header and a footer that incorporate the website's brand and style and is used on all pages. Some websites also have a sidebar that is used on all pages.
Let's take a look at an example to illustrate this, let's look at YouTube. On the home page, a header and video recommendations appear:

Scrolling to the bottom shows the footer with useful links after all of the video recommendations:

Now let's open a video and see how the top of the page looks:

As you can see, the header is identical and only the page's main content is different. Now let's look at the footer at the bottom of the page:
