What does this all mean?

Hits represent the total number of requests made to your site during that day.

Files represent the total number of hits that actually resulted in something being sent back to the visitor. Not all hits will send data, such as requests for pages that are already in the visitor's cache. Note: By looking at the difference between hits and files, you can get a rough indication of repeat visitors, as the greater the difference between the two, the more people are requesting pages they already have cached (have viewed already).

Pages are the whole page being requested, and not all of the individual items that make it up (such as individual graphics and text boxes).

Sites are the number of unique addresses that made requests to the site. Care should be taken when using this for analysis as many users can appear to come from a single address, and a single user can also appear to come from many addresses so it should be used simply as a rough guide as to the number of visitors to your site.

Visits occur when some remote site makes a request for a page on your site for the first time. As long as the same site keeps making requests within 30 minutes, they will all be considered part of the same Visit. If the site makes a request to your server, and the length of time since the last request has expired a new visit is counted. Only pages will trigger a visit, reducing the number of false visits.

KBytes (KB) is 1024 bytes (1 Kilobyte). This is the amount of data that was transferred from your site to the visitor's browser.