SIR

SIR stands for Susceptible Infectious Recovered model, also seen as Susceptible Infected Removed

Variations:
 * The SIS model
 * The MSIR model
 * The SEIR model, Susceptible Exposed Infectious Recovered
 * The SEIS model
 * The MSEIR model
 * The MSEIRS model

External

 * Wikipedia, Compartmental models in epidemiology

Simulators

 * gabgoh.github.io, Epidemic calculator
 * neherlab.org, covid-19 scenarios, with preset countries, regions