Connection pooling maintains a pool of reusable database connections to improve performance and reduce overhead of creating new connections repeatedly.

The next() method moves the ResultSet cursor to the next row and returns true if a row exists, false if no more rows. It's essential for iterating through results.

PreparedStatement offers faster execution due to precompilation and prevents SQL injection through parameterized queries using placeholders (?).

PreparedStatement is used for precompiled SQL statements with parameters. It provides better performance and prevents SQL injection compared to Statement.

executeUpdate() returns an integer representing the number of rows affected by INSERT, UPDATE, or DELETE operations. executeQuery() returns ResultSet.

getString() method retrieves String values from ResultSet. getInt() gets integer values, and fetchString/readString are not valid JDBC methods.

SQLException is thrown for database-related errors including connection failures. ClassNotFoundException occurs when JDBC driver class is not found.

Type 4 (Thin) drivers are pure Java drivers, platform-independent, and don't require native code. They communicate directly with database using Java sockets.

The correct JDBC sequence is: 1) Load the JDBC driver, 2) Create connection, 3) Create statement, 4) Execute query, 5) Process results, 6) Close resources.

Statement interface is used to execute SQL queries. Connection is used to establish database connection, ResultSet holds query results, and Driver manages database connections.