In database management, a join is a method used to combine records from two or more tables based on a related column. Joins allow users to retrieve data that is spread across multiple tables, making it easier to analyze and understand relationships within the data. There are several types of joins, including INNER JOIN, LEFT JOIN, and RIGHT JOIN. Each type serves a different purpose, such as returning only matching records or including all records from one table regardless of matches in the other. Understanding joins is essential for effective data manipulation and retrieval.