We all want to know how many visitors our website receives but it is important to understand the difference between hits, impressions and unique visits.
Hits - this simply refers to the number of 'elements' loaded on your site. If one page has five images in it, viewing that page once adds 6 hits (one page + five images).
Impressions - the number of times all the pages on your site are seen (also simply called pageviews). Impressions are sometimes referred to as 'hits' which can cause confusion.
Unique visits - the number of people that visited your site.
So to clarify, if a visitor visits your website and looks at two pages, and each page has 5 images on them, then your stats increase by one unique visit, two page views, and 12 hits.