J2EE
Java platform, enterprise edition (java ee) builds on the solid foundation of java platform, standard edition (java se) and is the industry standard for implementing enterprise-class service-oriented architecture (soa) and next-generation web applications. the sdks contain sun java system application server (sun's supported distribution of glassfish) and provide support for java ee 5 specifications.
http://java.sun.com/j2ee
J2ME
Java platform, micro edition (java me) is the most ubiquitous application platform for mobile devices across the globe. it provides a robust, flexible environment for applications running on a broad range of other embedded devices, such as mobile phones, pdas, televisie set-top boxes, and printers.
http://java.sun.com/j2me
J2SE
Java platform, standard edition, one of the most widely available and preferred client and server software platforms, serves as the cornerstone in sun's portfolio of developer products and services. java multiplatform support offers mission-critical java support for heterogeneous computing environments (e.g., solaris, linux).
http://java.sun.com/j2se
Java.sun.com
Whether you're creating software for mobile devices, desktops, enterprise systems, the internet, or games, java.sun.com gets you what you need: code samples, developer tools, downloads, open-source projects, resource centers, and support.
http://java.sun.com