**Preface to "Quantum Information Concepts in Open Quantum Systems"**

It has long been recognized that a key feature in determining the behavior of a quantum system is the interaction with the other surrounding quantum degrees of freedom. This aspect is crucial in foundational studies of quantum mechanics aimed at describing the quantum measurement process. At the same time, it plays a decisive role in the exploitation of quantum effects, especially in view of the implementation of quantum information schemes, quantum thermodynamic devices, and quantum technology applications. The theory of open quantum systems addresses all these challenges. Recent developments in the field have, however, shifted the activity toward considering and understanding the relevance of correlations, both of classical and quantum nature, in the description of the dynamics and measurement of open quantum systems. Indeed, duly keeping correlations into account both at the initial time and during evolution is a crucial requirement to pave the way for experimental advancements in the field of open quantum systems.

> **Bassano Vacchini, Andrea Smirne, and Nina Megier** *Editors*
