Common terms used in Google Analytics
With Google Analytics, a hit is ANY request sent to the GA data collection system. This includes pageviews, events, custom variables, measurement protocol uploads, etc.
You can backup your Google Analytics data by keeping a copy of the hits sent to Google. There are many good reasons to do this, as explained here: backup your Google Analytics data
A pageview is recorded every time a page is viewed. Or, more technically, a pageview is recorded every time the Google Analytics pageview tracking method is executed. When a user hits the back button, a pageview is recorded. When a visitor hits refresh, a pageview is recorded. Every time a page is opened in the browser, regardless of whether it has been cached, a pageview is recorded. (Of course this assumes the tracking code is on the page in question.)
A session consists of a series of pageviews that a single user makes during a period of activity. The session ends after the user either closes the browser, clears cookies, or is inactive for 30 minutes. (The timeout length is customizable in the tracking code settings)
Users are defined by a unique ID – this ID is usually stored in a cookie. Whenever the tracking code is executed, it looks for cookies on the browser set by the current domain. If they can’t be found, new cookies with a new ID are set. Google Analytics emphasizes sessions over users because of the inherent inaccuracies of trying to track individual users. For example, a user who deletes their cookies, uses multiple browsers, or shares their computer will be inaccurately represented in the reports.
A visit with one pageview. It doesn’t matter how long the visitor was on the page or how they left. Technically, it’s a visit with only one interaction.
Time on Page
Time on page is measured by subtracting the time a visitor hit a page from the time they hit the next page. (e.g. If they hit Page 1 at 12:00 and hit Page 2 at 12:03, time on Page 1 is three minutes.) This means that the time on page for the last page in a visit is always zero because Google Analytics doesn’t track pages being closed.
Time on Site
This is the sum of the time on page for all pageviews in a visit. Or, more accurately, it is the difference between the time they viewed the first page and last page in a visit. Note that viewing pages in different tabs doesn’t affect this. Google Analytics simply sees a string of pages being viewed in chronological order, without any reference to multiple tabs or windows.
A visitor who did not have Google Analytics cookies when they hit the first page in this visit. If a visitor deletes their cookies and comes back to the site, the visitor will be counted as a new visitor.
A visitor with existing Google Analytics cookies from a previous visit.
A measurement of how influential a page is to conversion. The higher the number, the more frequently it was viewed prior to a purchase or conversion. It’s calculated by taking the goal conversion value or transaction value of a visit and applying it evenly to all the pages prior to that conversion. Seen in aggregate, it just attempts to correlate pages to conversions.
Pageviews divided by visits. This metric shows the average number of pages viewed per visit.
Ideally, this is the traffic that came to a site via bookmarks or by directly typing in the URL. In reality, it is the traffic for which the code couldn’t determine a source. Depending on the site and the browser, some links may not show a referrer and instead would be categorized as direct. Using campaign variables will get around this misrepresentation every time.
This is traffic for which (1) a referrer was identified, (2) the referrer is not a search engine and (3) there are no campaign variables. The referring URL (a.k.a. the page that contains the link to your website) is also stored for referrals.
Search Engine Traffic
Google Analytics automatically categorizes traffic as coming from a search engine if the referring URL is from its list of known search engines and there is a search term identified in that URL. Both organic and paid search engine traffic is put into this group.
A feature that allows you to track visitor activities separately from pageviews. This is commonly used to track interaction with AJAX or Flash content.
Google Analytics API
The API extracts data from Google Analytics accounts. It allows customers to programmatically extract Google Analytics data and incorporate it with 3rd party applications and/or databases.