Each release of Java SE includes additional funcitonality that was either part of Java EE or separate functionlaity. For example, web services support was added to Java SE in version 6 (which, if you peruse the forums, you will see caused issues). So those statements indciate when certain functionlaity was provided within Java SE.
JBoss AS, on he other hand, track Java EE (previously J2EE) specifications. JBoss AS 4.0.x follows J2EE 1.5, AS 5.x follows Java EE 5 and AS 6 will follow Java EE 6. Sun's (or actually, Oracle's) web page on Java EE describes the individual features/functions/JSRs that are part of any given Java EE release. You will find that some of the functionality overlaps functionality provided in Java SE.