A database connection is a communication link between an application and a database management system (DBMS). This connection allows the application to send queries and receive data from the database. It is essential for applications that need to store, retrieve, or manipulate data, enabling users to interact with the information efficiently. To establish a database connection, developers typically use a connection string that includes details like the database type, server address, and authentication credentials. Common technologies for managing database connections include SQL, ODBC, and JDBC. Properly managing these connections is crucial for performance and security in software applications.