A pageview is the count a tool adds when it decides a page loaded. The tool defines the edges. A full reload is almost always another pageview. A client-side route change is a pageview only if the tool was notified. A request for a stylesheet is not a pageview, even though the server logged it.
Ten pageviews might be one person or ten. The metric does not say. Unique visitor is the attempt to count browsers once. Session is the attempt to group pageviews into a sitting. Neither grouping is inside the pageview itself.
A visitor counter is close to a pageview when its snippet is on every page you care about, and only then. The longer answer is what is a pageview. When you quote the number, name the tool. Two tools watching one site will not produce the same integer, and both can be "pageviews" by their own rules.
