Pageviews vs Unique Pageviews

What's the difference between a Pageview and a Unique Pageview?

Pageviews are defined as the total number of times the piece of content was viewed during a given period of time.  

Unique Pageviews represent an aggregate of pageviews generated by the same user during the same session (i.e. the number of sessions during which that page was viewed one or more times).  The time limit for a given session is 24hrs.

In other words, a pageview represents each time a user visits a page.  In this way, a single user loading the same page 5 times in a single session will generate 5 pageviews. Whereas unique pageviews are calculated on a session basis, meaning if the same user loads a page 5 times in a given session, it's only calculated as 1 unique pageview.  This is why pageviews will always outnumber unique pageviews.