PSA: The Master's Degree in Physics of Complex Systems is in the process of extinction since the academic year 2021/2022, so it does not admit new students. See section "Sobre la extinción del título" for more information. UNED degree catalog offers alternatives to this master's degree (see Master Degree in Advanced Physics).
This master´s degree is intended as an academic training and/or initiation to research in advanced physics, and complements undergraduate studies in Sciences (Physics, Chemistry, Mathematics) and Engineering. Students are allowed to establish their own curricular lines according to their expectations, being always adviced by a master´s tutor who is assigned by the Coordinating Committee.
From a general point of view, complex systems are characterized by a rich and complicated behavior rather than by their intrinsic definition. They appear in many and very diverse fields: Physics, Mathematics, Biology, Chemistry, Engineering, Economics, etc. These systems are characterized by the existence of a very high number of "agents" that interact with each other. As a consequence, new emergent behaviors, and in many cases surprising, arise.
Following the approach of Statistical Mechanics, which succesfully interpreted Thermodynamics as the macroscopic (emergent) statistical result of the interaction of a large number of atoms or molecules (microscopic agents), the more general field of Statistical Physics has extended its scope during the 20th Century to include these "complex systems", hence the current name of "Physics of Complex Systems".