Differences between classes12.jar, ojdbc5.jar,ojdbc6.jar and ojdbc14.jar

Jar File - Supported Java Version
classes12.jar - for Java 1.2 and 1.3
ojdbc5.jar - for Java 1.5
ojdbc6.jar - for Java 1.6
ojdbc14.jar - for Java 1.4 and 1.5
We need to add above jar's in server class-path based on JAVA version to connect datasource to the oralce Database