Java Editions

Sun has defined and supports four editions of Java targeting different application environments and segmented many of its APIs so that they belong to one of the platforms.

The platforms are:

Java Card:

for smartcards.

Java Platform, Micro Edition (Java ME):

Used to create programs that run on small handheld devices, such as phones, PDAs (personal digital assistants), and appliances.

Java Platform, Standard Edition (Java SE):

Used primarily to create programs for desktop computers or for any computer too large for J2ME and too small for J2EE.

Java Platform, Enterprise Edition (Java EE):

Used to create very large programs that run on servers managing heavy traffic and complicated transactions. These programs are the backbone of many online services, such as banking, e-commerce, and B2B (business-to-business) trading systems.

Each edition has different capabilities. It's important for you to know the differences among the editions because they affect your projects.

Be warned that the programs you compile for one edition will often not work for the other two editions.

J2SE compiled programs will work on J2EE because J2EE is a true superset of J2SE. J2EE programs that use special J2EE features won't work with J2SE, however. Nor will J2SE or J2EE programs run on J2ME, since the JVMs are quite different between the two editions.