I have a slightly differnet defenition
"hits - The number of times your site's server has been "hit" by a request for a web page or a graphic image"
hits- yes this is correct. a hit is any request to a web page of your site so if you have 9 images on a web page and one person sees its 9 hits this number is useless but its trackable to server logs report it. Ignore it.
"visitors (or sessions) - the number of pepole who have looked at your website"
visitors yes are sessions. a session is a time period that the server places on a visit to a web page usually 30 minutes. so I can visit a site at 9am and again at 1pm and I will be counted as 2 visits but if I go back many times within the same session it counts as one visit.
"unique vistors - the number of 'new' vistors (this ine is pretty obvious)"
this is not really number of new visitors its the number of unduplicated visitors. this si the number of people coming to your site for the unqie time period usually a month or a day. They count unquies by capturing the ip address. So if I come 5 times in one day I only get counted as one unique visitor but If I come to the site from a different computer with a different ip address I get counted twice.
I hope this helped I didnt like the other reply.
[edited by: engine at 5:15 pm (utc) on Feb. 6, 2004]
[edit reason] No urls, thanks. See TOS [webmasterworld.com] [/edit]