Stochastic Process → Definition → Poisson Process
Poisson Process is one of the most widely used counting process. It is used in conditions where some occurrences have certain rate (λ) but completely random.
For example, this office receives 1000 calls per day. the earthquake occurs in this area two times per year. In this particular road there are ten accidents per month.
In these cases, we know the rate (1000 calls per day, two earthquakes per year and ten accidents per month) but do not know the exact time when it occurs. These are at random.