Entanglement is a crucial resource in quantum information and I will explain how understanding its statistical properties can be used as a probe for the dynamics of a quantum system. In the first part, I will show how the typical entanglement entropy of six characteristic ensembles reproduces the typical entanglement entropy of energy eigenstates, which allows us to discriminate between integrable and quantum chaotic systems. In the second part, I will present a general formula for the typical entanglement entropy in any system with a fixed number of quantum particles.