The Java platform is a set of programs that help developing and running programs written in the Java programming language.
Is that clear ?
Now,the platform is not specific to any one processor or operating system, rather an execution engine (called a virtual machine) and a compiler with a set of libraries are implemented for various hardware and operating systems so that Java programs can run identically on all of them.
There are multiple platforms, each targeting a different class of devices:
- Java Card: for smart cards and similar small-memory devices.
- Java ME (Micro Edition): Used to develop applications for mobile devices, PDAs, TV set-top boxes, and printers.
- Java SE (Standard Edition): For general-purpose use on desktop PCs, servers and similar devices.
- Java EE (Enterprise Edition): Java SE plus various APIs useful for multi-tier client–server enterprise applications.
Now J2EE :
Java Enterprise Edition from version 1.2 till 1.4 comes under J2EE
Versions from 1.5 are termed Java EE or JEE
Now we have JEE 7 and 8 will be out soon.
Final Note :
Based on the requirements you can change over to updated versions.
J2EE & JEE 7 :
Find more at eCourses at enggforum on Java :