It refers to the request made to load a HTML page.

The major role played by Page views is that they help determine the revenue model of a particular site. That is where their importance lies. If the site earns a major portion of its income through advertisements displayed on it, then page views plays a significant role in it. This is so because page views add on to the inventory of advertisements on the site. However, Page views do not assume much significance if the site under observation earns a major chunk of its revenues from other sources like sales. Page views minus sales can often equated as an additional expense.