# A Basic Introduction to Epidemic Modelling

A standard technique to model the spread of epidemics is through a **compartmental model**. In such models, we divide the population into different categories or compartments according to the infection stage (such as “Susceptible”, “Infected”, and “Recovered”, for example). Since individuals can proceed through the different stages of the infection over time, we also incorporate transition rates between these compartments. In the following section we offer an introduction to a basic, but surprisingly effective compartmental model, the **SIR model**.