Pageviews are the total number of pages viewed. Repeated views of a single page are counted.
Unique Pageviews are the number of visits during which the specified page was viewed at least once. A unique pageview is counted for each page URL + page Title combination.
The average amount of time users spent viewing a specified page or screen, or set of pages or screens
Entrances are the number of times visitors entered your site through a specified page or set of pages.
Bounce Rate is the percentage of single-page visits (i.e. visits in which the person left your site from the entrance page without interacting with the page).
%Exit is (number of exits) / (number of pageviews) for the page or set of pages. It indicates how often users exit from that page or set of pages when they view the page(s).