In this section, we will not only discuss why one might want to use Event Sourcing—we will also look into the definition of this pattern and some history behind it. Like Greg Young often puts it, "Event Sourcing is not new", and we will get into some history that should help you to understand the concept better.
After that, we will get into the why part. Armed with some knowledge about its history, it won't be very hard to understand why this way of storing data is becoming more popular.
By the end of this section, we will make it clear why one might not want to use Event Sourcing in their system, and what challenges are awaiting those who start using it for the first time.