Explore compartmental models for infectious disease dynamics in this comprehensive lecture, the second of a four-part series delivered by Roberto Kraenkel from IFT-UNESP. Delve into advanced concepts and techniques used to analyze and predict the spread of infectious diseases. Gain valuable insights into the mathematical foundations and practical applications of these models, essential for understanding epidemiological patterns and informing public health strategies. Part of the School on Modelling Infectious Disease Dynamics organized by ICTP-SAIFR, this 90-minute session offers a deep dive into a crucial aspect of epidemiology and mathematical biology.