Optional packages in Java

Optional Packages are packages of Java classes which are used to extend the core Java platform.

Optional Packages are created by Java developers much like any other Java code. Optional Packages are then made available to the Java Virtual Machine.

Java classes stored within Optional Packages can be used by the JVM without the need to be explicitly included in the CLASSPATH.

Optional Packages are usually stored in JAR files.

In earlier versions of Java, Optional Packages were known as Standard Extensions.