1. Ordinary differential equations study continuous time changes. By solving equations, we need to master mathematical tools such as calculus and linear algebra, and have certain geometric intuition.

2. Stochastic process is to study the model based on probability and random variables, and analyze the basic characteristics of stochastic process, such as randomness, independence, Markov and stationarity. The mastery of stochastic processes requires probability theory, and the knowledge required is less than that of ordinary differential equations, so ordinary differential equations are relatively difficult.