At the highest levels in the organization (CEO and CFO), there are two revenue churn measurements that are typically important.
Churn from lost/canceled customers – typically reported as the value of the term or contract had it renewed
Churn from downgrades – typically reported as the net decrease in the value of the term or contract had it renewed at the previous term rate
As you move down and/or into other business units or functions, it is common to report churn at a more detailed level. For example, the sales team is frequently not held accountable nor given relief for cancellations due to bankruptcy and mergers, so you will often see this metric from lost/canceled customers broken down by reason codes.