The first return map is a mathematical tool used to analyze chaotic systems. It tracks the behavior of a system by plotting the position of a point after it returns to a specific reference point or surface. By analyzing the return map, researchers can identify patterns, attractors, and other characteristics that provide insights into the system’s chaotic behavior. It helps visualize the long-term behavior of chaotic systems and is particularly useful in understanding phenomena such as fractals, Julia sets, and the Cantor set.