Java is an object-oriented programming language launched in 1995. Once compiled, a Java program can be executed on any machine supported by the JVM (Java Virtual Machine).
One of the key advantage of Java over native programs is that the memory management is greatly abstracted safer operations and simpler implementations.
J2se is the Java platform for data-structures, i/o, user interfaces, sql, xml and many standard software components. J2ee is an extension of features for enterprise applications.