“JDK” is the Java Development Kit. I.e., JDK is a bundle of software that you can use to develop Java based software. The “JRE” is the Java Runtime Environment. I.e., the JRE is an implementation of the Java Virtual Machine which actually executes the Java Programs.Typically, each JDK contains one (or more) JRE’s along with the various development tools like the Java source compilers, bundling and deployment tools, debuggers, development libraries, etc.
What are JDBC Drivers?
JDBC Drivers are set of classes that enables the Java application to communicate with databases. Java.sql that ships with JDK contains various classes for using relational databases. But these classes do not provide any implementation, only the behaviours are defined. The actual implementaions are done in third-party drivers. Third party vendors implements the java.sql.Driver interface in their database driver.