Just what is the Java API anyway? – JavaWorld

The Java API is the set of classes included with the Java Development Environment. These classes are written using the Java language and run on the JVM. The Java API includes everything from collection classes to GUI classes. You can view a complete listing of the Java API at: “Java 2 Platform, Standard Edition, v 1.3.1 API Specification.”

Tutorials are also available at: “Java Tutorial.”

Ah, like intrinsics or libraries?