
# Terms

## MRR
Monthly Recurring Revenue. Sum of active
[subscriptions](/tables/subscriptions.md) at month end.

## Churn
Rate at which [customers](/tables/customers.md) cancel their
[subscriptions](/tables/subscriptions.md) per month.

## Dunning
Automated retry of failed subscription renewals, handled by the
[billing service](/services/billing.md) via Stripe.

## Event sourcing
Persistence pattern where state is reconstructed from an append-only
event log. See [ADR: event sourcing](/decisions/adopt_event_sourcing.md).
