Hits verses Accesses

This is a very important distinction between Requests and Accesses. When a page is requested from the server, it may contain, for example, four images. When this occurs, the access log will record five "hits" - one for the HTML Web page and four for the four images. However, when you wish to track your statistics, you will typically not be interested in the number of images that are requested. In this case, you will wish to know the accesses number.

Also a framed website can increase the accesses number as you can load several HTML pages for each frame. There is a way to reject the master frame pages in this package (page which define other framed pages).

Hosts versus visitors

The Web server typically does not know how many users come to your web site. Here's why: After the Web server sends you a Web page of information, the server computer typically breaks the connection with you. Then when you request a second Web page from that computer, you establish another quick connection, in which it again sends you a web page and breaks the connection. Unless there is special software on the Web server (e.g., cgi script or cookies), the log files cannot know for sure that it is the same person.
However there is a way to estimate the visitor number from the log file assuming some basic rules. Check the session section to know more.
The number of different hosts is a first guess and should be use carefully (proxy tends to decrease this number but dhcp protocol (used by most internet providers) tends to increase this number !).

Requests
(or hits)
This term refers to the number of files that are downloaded from a web server. Keeping track of hits is a way of measuring traffic to a website that can be misleading. Avoid to use it.
However ratio accesses/hits can be interesting.
Accesses
(or page view)
Accesses correspond to hits on HTML pages. This is a accurate way to know how popular is your website. Page parsing can be defined in the configuration file from extension (html, htm, php ...)
Traffic (or bandwith)
Bandwidth is the total number of bytes transferred. This can be helpful to know how much bandwith is used by your website.
Differents pages
This show the number of different pages being read by users. This number should be compare to your total number of HTML pages and the ratio tell you how much is rather too old or not interesting for users. A ratio near 1 mean a well done website !
Hosts (or visitors)
Hosts correspond roughly to the total number of people who visited the site assuming one hostname is one person (so I prefer to use 'Hosts' rather than 'visitor'). This can be inaccurate due to the effects of web caches and proxies. Check the session section if you need an accurate visitor number.
Countries
The easy way to know if your website is popular around the world. Check the countries section to get more statistics. In order to get these stats, you should use the reverse dns option if you're using a pure IP logfile. The Geo module will help to translate unresolved IP if enabled.