These notes illustrate the basic elements for analysis and design of linear control systems. With 15 chapters and an appendix of 4 sections the notes start from the notion of mathematical model (system), explaining its important role in the study of a phenomenon and how linear models can arise in practice. Through the time and Laplace analysis the behaviour of a linear model is studied in detail. The basic notions of stability, steady-state and transient response and structural properties give a deep insight in the study of the behavior of an abstract model. In this first part of the notes,...