>> terms like "Hits, Files, Pages, Visits, Sites, KBytes"
Hits: Most stats programs just use the term hits to mean any request for a document (webalizer seems to call this "files" and uses the term "hits" to also include other types of requests that don't return files on the filesystem, like 404s).
Example: Let's say your homepage, index.html, has three images on it. When someone visits your homepage, the server will record 4 hits: one for the index.html document, and one for each of the three images it had to fetch to complete the page.
Usage: Hits is useful to see how hard your server is getting hammered.
Pages: This is the number of page views, ignoring imbedded images and such.
Example: Let's say your homepage, index.html, has three images on it. When someone visits your homepage, the server will record 1 page view.
Usage: Useful metric to determine how many and what individual pages of your site are being viewed.
Sites or Unique Visitors: Usually called unique vistors, this is a deduction of how many "people" visited your site. Usually bbased on IP address and sometimes other factors as well. This is always an estimation since there is no accurate way to measure that. Therefore different stats programs could come up with different numbers using the same log file.
Example: A visit from User A at IP address X would count as one unique vistor, regardless of how many pages they viewed or how many hits they generated.
Usage: Great metric to estimate the number of unique people that visit your site. Your reach.
Visits: A visit is a unique vistor's session measured by some period of time (like 30 minutes or an hour). Subject to the same innacuracies as Unique Visitors.
Example: If User A at IP address X viewed 7 pages and 16 graphics in a 30 minute period of time, that would count as one visit. If that same user came back to the site the next day and viewed 3 more pages, that would count as another session or visit.
Usage: Great to see how often people are coming to the site.
Bytes or Bandwidth: This shows the amount of bandwidth sent across the pipe.
Example: If your homepage is 14k plus 3 images at 12k each, then when a typical user requests that page they'll pull 50k of bandwith (14+12+12+12).
Usage: See your bandwidth usage.
Reading the numbers...
Example: 100 unique visitors, 300 visits, 1200 page views, 3600 hits, 2.2GB bandwidth
This means an estimated 100 different people have visited. Those 100 people visited on average 3 times each (300 visits / 100 uniques). During each of those 300 visits, those 100 people viewed an average of 4 pages each (1200 page views / 300 visits). Those 1200 page views generated and average of 3600 hits, or 3 hits per page. All together, 2.2GB of bandwidth was consumed.
2.2GB of bandwidth is a lot for that level of traffic. Unless they are movies, the graphics could be way too big. 3 hits per page view? Are images being cached appropriately? Could signal some coding inefficiencies.
The number of visits being higher than the numkber of uniques is good. Means you have repeat visitors.
4 page views per visitor, how good/bad that is depends on the site. Measures the "stickiness" of your site.