http://en.wikipedia.org/wiki/Web_analytics
http://www.ochs.org.uk/sites/all/files/GoogleAdvertisingTools.pdf
Hits:
Definition: A depreciated metric that counts each call to specific files separately. Each page is comprised of a variable number of hits.
Value: Hits are of little to no value because trend analysis is difficult based on the high degree of variability.
Page Views
Definition:
Represents the number of times pages were viewed (e.g. publication pages, about us pages, advocacy pages) in a defined period (e.g. month).
Value: Can provide trend analysis over time since a page is less variable than a hit.
Visit Session
Definition:The number of times a site is visited within a specified time frame by humans, spiders, and bots. Typically, a visit is comprised of multiple page views.
Value: Provides a trend of overall site usage. Does not factor out repeat usage by the same visitors.
Unique Visitors
Definition: The number of individual visitors to the site, filtered for duplicate sessions and spiders and bots.
Value: This metric can provide the surest signs of overall usage growth but remains challenging to track accurately.
Spiders and Bots
Definition: Spiders and bots crawl the web looking to index content for search engines.
Value: Spiders and bots can help your search engine rankings as they crawl and index your site.
Referring Sites
Definition:
Sites that originate traffic to your web site. Typically reported separately from search engines and direct traffic (traffic from emails, bookmarks, etc).
Value: These help you know how your visitors are finding you and which sites that link to you get are the most valuable from a traffic perspective.
Keywords
Definition: Terms used by visitors originating from search engines.
Value: Provide direction as to which words visitors are using to get to your site. Should be looked at in conjunction with bounce rate to help determine which keywords you want to focus your Search Engine Optimization (SEO).
Bounce Rate
Definition: Percentage of visitors who leave your site immediately upon visiting
Value: When looked at in tandem with search keywords and specific pages, bounce rate can help you determine which keywords to optimize for and help determine problem pages.
Content Drill Down
Definition Content drill down shows which specific pages of your site are viewed and how many views each page received.
Value: You may be surprised to learn that pages you don’t spend time updating are more viewed/popular than pages you update regularly. Drilling down can help you focus your efforts.
Click Path
Definition Illustrates common paths your visitors take within your site.
Value: Common paths can help you get an understanding of how visitors are interacting with your content and which pages they are visiting
sequentially.
Entrance Page
Definition This metric shows which pages your visitors are using as their starting point with your site.
Value: This metric can help you with content direction. If pages other than your home page are your biggest entry pages, you may want to add specific content to those top pages.
Exit Page
Definition Like entrance page, exit page helps you determine where visitors are leaving your site.
Value: This metric can help you with content direction. For top exit pages, ask yourself, is this exit page at the end of a process (e.g. registration or joining) and, if not, why did the visitor leave on this page?
Conversion
Definition The % of visitors who complete a conversion event, such as registering for an event, joining, purchasing a publication
Value: Conversion can help measure success of online initiatives by showing how small changes or improvements increase overall conversion.
Abandonment Rate
Definition The % of visitors who do not complete a conversion event, such as registering, joining, purchasing a publication, etc.
Value: Looking at trend of abandonment as well as where in the process people are leaving can help both tighten the process as well as measure success.