If you haven't heard about event sourcing or are unsure about what it is, Barry O Sullivan has got you covered. Recently he wrote up a blogpost that explains it very clearly.

Event Sourcing (ES) is opposite of this. 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. ... It solves all the big problems our team has faced when building large scale distributed business software. It allows us to talk to the business in their language, and it gives us the freedom to change and adapt the system with ease.