Visits  Visits
This is the total visitors to your site for the period (hour/day etc).If a vistitor to your site visits and revisists within 24 hours - they are recorded as 2 visits.
The +/-% change relates to the previous period (e.g if day selected then previous hour).

Unique Visitors  Unique Visitors
Unique visitors are counted only once in a 24hour period, thus if the same person, visits the site multiple times during the same 24hour period they will only be counted once.
The +/-% change relates to the previous period (e.g if day selected then previous hour).

Page views  Page views
This is the total number of pages that have been viewed by all visitors in this period. Note that this is only where you have installed our tracking code. We cannot track pages where our tracking code is not installed - thus you may be getting incomplete data if tracking code is not installed on all of the web sites pages.
The +/-% change relates to the previous period (e.g if day selected then previous hour).

Maximum online  Maximum online
The maxmium online is the total number of visitors who are viewing the website at the same time. Due to the nature of web Technology we time users sessions out after a period of time, thus maximum online values are likely to have a margin of error.
The +/-% change relates to the previous period (e.g if day selected then previous hour).

Average online  Average online
Average number of visitors online during this period.
The +/-% change relates to the previous period (e.g if day selected then previous hour).

Minimum online  Minimum online
Minimum number of visitors online during this period.
The +/-% change relates to the previous period (e.g if day selected then previous hour).