The term "extensive" refers to something that covers a large area or involves a significant amount of detail. It can describe physical spaces, such as an extensive forest or extensive farmland, indicating that these areas are vast and spread out. Additionally, "extensive" can apply to knowledge or research, suggesting a thorough and comprehensive understanding of a subject. In various contexts, "extensive" often implies a high degree of breadth or scope. For example, an extensive study might involve numerous participants and cover multiple aspects of a topic, while an extensive collection could refer to a large assortment of items, such as books or artifacts, showcasing diversity and richness.