Understanding Statistics Terminology

Having detailed website statistics is useless unless you understand how to read the statistical information collected. The information below explains how to read your website statistics and has been compiled from AWStats Online Reference Manual.

Unique Visitor:
A unique visitor is a host that has made at least 1 hit on 1 page of your web site during the current period shown by the report. If this host make several visits during this period, it is counted only once.
The period shown by AWStats reports is by default the current month.

Visits:
Number of visits made by all visitors.
Think "session" here, say a unique IP accesses a page, and then requests three others without an hour between any of the requests, all of the "pages" are included in the visit, therefore you should expect multiple pages per visit and multiple visits per unique visitor (assuming that some of the unique IPs are logged with more than an hour between requests)

Pages:
The number of "pages" logged.
Usually pages are reserved for HTML files or CGI files, not images nor other files requested as a result of loading a "Page" (like js,css... files).

Hits:
Any files requested from the server (including files that are "Pages").

Bandwidth:
Total number of bytes for pages, images and files downloaded by web browsing.
Note 1: Of course, this number includes only traffic for web only
Note 2: This number does not include technical header data size used inside the HTTP or HTTPS protocol or by protocols at a lower level (TCP, IP...).
Because of the two previous notes, this number is often lower than bandwith reported by your provider (your provider counts in most cases bandwitdh at a lower level and includes all IP and UDP traffic).

Entry Page:
First page viewed by a visitor during its visit.
Note: When a visit started at end of month to end at beginning of next month, you might have an Entry page for the month report and no Exit pages.
That's why Entry pages can be different than Exit pages.

Exit Page:
Last page viewed by a visitor during its visit.
Note: When a visit started at end of month to end at beginning of next month, you might have an Entry page for the month report and no Exit pages.
That's why Entry pages can be different than Exit pages.

Session Duration:
The time a visitor spent on your site for each visit.
Some Visits durations are 'unknown' because they can't always be calculated. This is the major reason for this:
- Visit was not finished when 'update' occured.
- Visit started the last hour (after 23:00) of the last day of a month (A technical reason prevents AWStats from calculating duration of such sessions).

Grabber:
A browser that is used primarily for copying locally an entire site. These include for example "teleport", "webcapture", "webcopier"...

Direct access / Bookmark:
This number represent the number of hits or ratio of hits when a visit to your site comes from a direct access. This means the first page of your web site was called:
- By typing your URL on the web browser address bar
- By clicking on your URL stored by a visitor inside its favorites
- By clicking on your URL found everywhere but not another internet web pages (a link in a document, an application, etc...)
- Clicking an URL of your site inside a mail is often counted here.

Add To Favourites:
This value, available in the "miscellanous chart", reports an estimated indicator that can be used to have an idea of the number of times a visitor has added your web site into its favourite bookmarks.

HTTP Status Codes:
HTTP status codes are returned by web servers to indicate the status of a request. Codes 200 and 304 are used to tell the browser the page can be viewed. All other codes generates hits and traffic 'not seen' by the visitor. For example a return code 301 or 302 will tell the browser to ask another page. The browser will do another hit and should finaly receive the page with a return code 200 and 304.

Other articles that may help:

What Are Website Statistics?
What Statistics Software Do You Use?
How Do I Access My Website Statistics?
Understanding Statistics Terminology