Glossary
Conversion
Any measurable, successful outcome of a website visit- such as registering an account, making a purchase, or donating to a cause.
Conversions mean different things to advertisers. For online retailers, a successful conversion could be the sale of a product to a visitor that viewed (and clicked) on a banner ad. For informational sites, a successful conversion could be a download, newsletter subscription, or other action that's achieved once the advertiser requests the visitor to take the action.
See Conversion Rate, and Yield