The supermost package of Java is the "java" package.

a package

The Java 'this' installation package allows one to create installation programs for their Java based applications. One can download the program from Java.

A default package is a package with no name. You can create a Java class without putting package name on top of the code. This class is included in the "default package".

Be careful not to be confused with java.lang, which is a package that contains Java's fundamental classes and get's imported by default.

The java.lang package is automatically imported for you.