Metrc (Marijuana Enforcement Tracking Reporting and Compliance) is a web-based application that State Licensees upload marijuana inventory data as required by regulation. Metrc (formerly Franwell) is "an enforcement tool developed to track and monitor marijuana inventory within the State’s regulated, closed-loop Medical/Retail Marijuana regulatory scheme."
Metrc allows real-time tracking and tracing of cannabis. Licensees are able to attach unique, serialized tags or UIDs (unique identifiers) to every plant and/or package. A cannabis plant is then tracked all the way from seed to final sale to the consumer using these tags which accompany the plant throughout its lifecycle.
More information can be found here.