A visit is any time a visitor reaches your shop website from somewhere outside of your shop's domain. This means that the person was on a different website and followed an ad or link to reach your store, or that they entered the address directly into your browser (this is also known as "Direct Traffic")
If the visitor was already on your shop, navigating to a different page on the won’t count as a new visit, as it is the still the same visitor.
Visits are measured and tracked using cookies. AdCurve tracks each page-view to check the source of the visitor, and and to track new sessions or visits.