从这个***条目：

JDK是一个在一般意义上，松散定义为软件开发工具包（SDK）的子集。在最近发布的Java SE，EE和ME附带的描述中，Sun承认，在他们的术语中，JDK构成了SDK的子集，负责编写和运行Java程序。 SDK的其余部分由额外的软件组成，例如应用程序服务器，调试器和文档。

The JDK is a subset of what is loosely defined as a software development kit (SDK) in the general sense. In the descriptions which accompany their recent releases for Java SE, EE, and ME, Sun acknowledge that under their terminology, the JDK forms the subset of the SDK which is responsible for the writing and running of Java programs. The remainder of the SDK is composed of extra software, such as Application Servers, Debuggers, and Documentation.

额外的软件似乎是Glassfish，MySQL和NetBeans。 此页面比较了您可以获得的Java EE SDK各种软件包。

The "extra software" seems to be Glassfish, MySQL, and NetBeans. This page gives a comparison of the various packages you can get for the Java EE SDK.