Java Database Connectivity (JDBC) is an API for connecting Java applications with various databases, allowing execution of SQL statements and retrieval of results. There are four types of JDBC drivers: Type-1 (JDBC-ODBC bridge), Type-2 (native API), Type-3 (network protocol), and Type-4 (thin driver), each with distinct advantages and disadvantages. The thin driver, known for its pure Java implementation, provides better performance as it interacts directly with the database without needing native libraries.