This article uses the terms "visit" and "pageview" in unusualy ways.
They give the example that when a user clicks through from yourwebsite.com/ to yourwebsite.com/page then the first is a unique visit while the second is a non-unique visit.
I would neither call a "visit" but rather a "pageview".
In my book, the visit is what started from the first pageview on yourwebsite.com site and continues to the last pageview.