The most fundamental metric in Web measurements is the page view, which is just what it sounds like--a count of how many Web pages have been shown to your site's visitors.

Web metrics reports always summarize page views for a particular time period, so you can see how many page views occurred in a day, a week, or a month.

By analyzing the trends of page views, you can see if your views have gone up this month from last month, or from the same month last year. (For a toy retailer, comparing January's page views to those of last January is usually more instructive than comparing to the Christmas-inflated December numbers.)

More importantly, the page views of individual pages can be analyzed, so that you can see which particular pages on your site have been viewed the most, and you can analyze the trends for each page over time.

More interesting than analyzing page views is examining just who is viewing those pages. Most Web metrics programs can identify a series of pages that have been viewed by the same visitor, by using cookies.

The Web metrics program "drops" a cookie file on each visi-tor's computer when she enters the site. This file contains a unique identifier not shared by any other computer's cookie. The Web metrics program reads the identifier from the cookie file each time a page is viewed and remembers which computer viewed that page.

Identifying visitors allows metrics programs to provide you with better information. Now, instead of merely counting page views, you can count the number of visits to your site.

Visits, sometimes called sessions by some metrics facilities, let you see how many people are coming, not just how many pages were viewed by all people. For example, two Web sites might each show 100 page views, but one has four visits with 25 page views each while an-other might have ten visits that average 10 views each. If you count just page views, all you know is that 100 pages were viewed.

If you count visits, you know that one site got four vis-its, but they stayed and looked around for a while, while the other site got 10 visits from people who looked at fewer pages in each visit.

This information is critical, because you can't get more conversions from more page views-you get more conversions from more visits.

In addition to identifying visits, you can also track the number of visitors (sometimes called unique visitors), because you can track whether the same visitor has returned to your site multiple times.

So the metrics report could show 100 page views in ten visits by eight different visitors, because a couple of those eight visitors had more than one visit.

This is important as well, because for many Web sites, people tend to visit multiple times before they convert, so knowing the number of new versus returning visitors can tell you even more than tracking visits alone.

Conversion is a sales term that refers to converting prospects into customers, and you may often hear about a business raising its conversion rate, the ratio of "lookers" to "buy-ers."

For a Web sales business, you can think of the conversion rate as the number of visitors divided by the number of orders. Raising the sales conversion rate means that you book more sales with the same number of folks coming into the "store" (your Web site).

Salex conversions are only one kind, however. Every Web site has a goal for its visitors to achieve, which we are now calling a Web conversion. For example, your Web site's goal may be creating as many leads to an offline channel as possible.

Perhaps you've placed a form on your Web site that allows visitors to provide their contact information, which gets routed to your offline sales force. You can treat each completed contact form as a Web conversion, and you can calculate your Web conversion rate.