Multi-planet systems refer to star systems that contain more than one planet orbiting around a central star. These systems are of great interest to astronomers as they can provide valuable insights into the processes of planetary formation and evolution. By studying the properties and dynamics of multiple planets within a system, researchers can better understand the complex interactions between planets and their host stars, as well as investigate how different planetary configurations may affect the overall system's stability and architecture. Multi-planet systems are also important for advancing our understanding of planetary diversity and the prevalence of habitable environments in the universe.