What do you mean what does it mean? It's a study of stochastic processes. If you really want to wonder what something means, check out what I discovered here: https://math.stackexchange.com/ques...-in-the-complex-plane-and-calculating-its-len btw even after these brilliant contributions to math stack exchange, I was banned until 2047 for daring to leave my email address in an answer to someone there because SE doesnt have any private messaging capabilities.