Traditional databases store the current state of data. When you update a customer's address, the old address is gone. The database tells you what is, but not how it got there.

Event sourcing takes a fundamentally different approach. Instead of storing current state, you store a sequence of events that describe everything that happened. The current state is derived by replaying these events. Nothing is ever deleted or updated in place. Every change is recorded as a new event.

In this chapter, you will learn:

State-Based vs Event-Sourced