There are one or two bits of terminology that often cause confusion:

Hit Any request made to the server
File Any request made to the server that resulted in something being sent back (produced error code 200 - OK)
Page By default any file with extensions htm, php, cgi, php, php3, phtml, pl. There may be other extensions that you might consider to be a page and the list can be edited in Options.
Visit A sequence of accesses all from the same IP address with no interval between accesses exceeding 30 minutes. Only pages will trigger a visit count so sites that "hotlink" directly to images will not be recorded as a visit. Visits are not yet implemented in LogAnalysis but will be added in future versions.
Entry The word entry generally refers to the first access of a visit (see above). So the entry file would be the first file to be accessed in a single visit.
Image By default any file with the common image extensions jpg, jpeg, gif, bmp, png, ico. There are many more image file extensions but to test for them all would be very slow however the list can be edited in Options.
Referrer This is the complete URL of where the access came from and may include form values such as search strings
This is just the domain part of the Referrer eg. www.mydomain.com
This identifies the type of browser that the request came from