Command and Query Responsibility Segregation (CQRS) is a technique that has become popular in the last few years as a means to scale reads and protect the encapsulation of domain objects optimally. However, it is usually presented in combination with other topics (Event Sourcing, DDD, Microservices), which gives many developers a hard time understanding what is part of CQRS and what is not. Here, we will try to explain the idea of CQRS and how we can take advantage of it, under what circumstances, and the price we have to pay for it.