How Java EE Relates to J2SE ?

Java EE isn’t a replacement for the Java 2 Standard Edition (J2SE). J2SE provides the essential language framework on which Java EE builds. It is the core on which Java EE is based. As you’ll see, Java EE consists of several layers, and J2SE is right at the base of that pyramid for each component of Java EE.
As a Java developer, you’ve probably already learned how to build user interfaces with the Swing or Abstract Window Toolkit (AWT) components. You’ll still be using those to build the user interfaces for your Java EE applications, as well as HTML-based user interfaces. Since J2SE is at the core of Java EE, everything that you’ve learned so far remains useful and relevant.
In addition, Java EE provides another API for creating user interfaces. This API is named JavaServer Faces (JSF) and is one of the newest Java EE technologies. You’ll also see that the Java EE platform provides the most significant benefit in developing the middle-tier portion of your application—that’s the business logic and the connections to back-end data sources.
You’ll use familiar J2SE components and APIs in conjunction with the Java EE components and APIs to build that part of your applications.