Final answer:
Database developers use the DBMS to create relationships in databases, utilizing primary and foreign keys defined in table columns.
Step-by-step explanation:
Database developers use the DBMS (Database Management System) to create relationships in the database. The DBMS is a software tool that enables database developers and administrators to create, manage, and interact with databases. It provides functionalities for defining database schemas, and thus, specifying how data is structured within the database through the use of tables, which consists of columns and rows. To establish a relationship between different entities in the database, developers usually make use of keys, such as primary keys and foreign keys, which are defined within the columns of the tables, and these keys help maintain the integrity of the data by ensuring that the relationships between tables are logically coherent.