Instead of focussing on current state, you focus on the changes that have occurred over time. It is the practice of modelling your system as a sequence of events.
Event Sourcing domain expert won't talk about “tables” and “joins”, they'll describe processes as the series of events that can occur and the rules applied to them.
- State of data is a stream of events
- Eases auditing
- Eventual Consistency
- Distributable stream through a Message Bus