A Petri Net is a mathematical modeling tool used to describe and analyze systems that involve concurrent processes. It consists of places, transitions, and tokens. Places represent conditions or states, transitions represent events that can change these states, and tokens indicate the current state of the system. This structure allows for visualizing how different parts of a system interact and evolve over time. Petri Nets are widely used in various fields, including computer science, networking, and manufacturing. They help in understanding complex systems by providing insights into their behavior, such as identifying bottlenecks or ensuring that processes run smoothly.