  This text is a short introduction to the physics of driven-dissipative
many-body systems, focusing on a few selected topics. Beyond its more
``historical'' interest in the study of atomic physics and quantum optics,
presently the modeling and studying dissipative phenomena in open quantum
systems is pivotal to understanding quantum hardware platforms. While the lack
of a thermodynamic potential for these out-of-equilibrium open systems makes it
theoretically challenging to investigate their physics, at the same time it
allows going beyond the thermodynamic paradigms and investigating new and
exotic phenomena. We will focus on one of the simplest, yet most effective,
descriptions of open quantum systems, namely the
(Gorini-Kossakowski-Sudarshan-) Lindblad master equation. This phenomenological
approach describes quantum systems that weakly interact with their surrounding
environment. Although many of the results derived below will apply to any
quantum system, we will focus in particular on bosonic/spin systems.
