This lecture provides an introduction to the EPFL course on Signals and Systems, outlining the course organization, materials, and evaluation methods. The instructor discusses the importance of mathematical tools for modeling real systems across various engineering domains. Key topics include linear time-invariant systems, frequency response, and Fourier techniques. The course aims to equip students with the necessary skills to analyze and design systems, emphasizing the relationship between input signals and system outputs. Practical examples, such as automotive suspension systems and audio compressors, illustrate the concepts. The instructor highlights the theoretical nature of the course while assuring students of the relevance of the material to their future studies in electrical engineering. The lecture concludes with an overview of the course structure, including mid-term and final evaluations, and encourages student interaction throughout the sessions.