So I (Yvvy) am taking a differential equations class right now, and we've looked at some SIR and SID models for the spread of disease. I, as a student addicted to trying to code literally everything I can, decided that hey, instead of using just the math of the differential equations, we could make a simulation to see how the math actually plays out. So, we started with the differential equations, then decided to make the model more complicated. So we included exposed and dead people to the SIR model, resulting in a SEIRD model. Our simulation takes into account the "exposure" of people to others who are infected, resulting in the "rate of infection" dI/dt being played out through the sim.