Question on Statistics Add-onBrowser Info Environment
A site visit is when someone comes to your site. If they visit 1 page or 20 pages it still counts as just one site visit. A page view is how many pages are opened.
Timed out means that the user opened a page and just let it sit there for a long time, and the stats system was never notified that the page was closed, so it's assumed that the visit ended. It can't say how long he visited the last page he was on for this reason. The default timeout period is 20 minutes of inactivity.