A UTM code is a basic URL parameter that is appended to existing URLs that provides additional granularity to Google Analytics for tracking marketing channels and even individual campaigns within a single marketing channel. Google has 5 UTM parameter values available with 2 that represent the minimum needs for them to be able to assign visitors to channels. The 2 critical UTM tags are: utm_source and utm_medium. The additional optional UTM tags that are available are: utm_campaign, utm_term and utm_content. The combination of these is provided in order to allow a marketer to track more and more granular information tied to any individual marketing effort through Google Analytics.