The Urchin Tracking Module (UTM) is a system for tagging and tracking URLs in order to measure the performance of online marketing campaigns. The UTM system was developed by Urchin Software Corporation, which was acquired by Google in 2005. UTM tags are added to the end of a URL, and they consist of a series of parameters and values that provide information about the source, medium, and content of the link. For example, a UTM tag might include the name of the campaign, the name of the advertiser, the name of the ad group, and the name of the ad. When a user clicks on a link with a UTM tag, the parameters and values are passed along to the destination page, and they can be used to track and measure the traffic and conversions generated by the campaign. UTM tags are commonly used in email marketing, social media marketing, and paid search advertising, and they can be managed and analyzed using tools such as Google Analytics.