Java SE Core Technologies - Basic Technologies

Java SE contains a rich set of APIs that enable developers to create sophisticated applications. They provide both fundamental system level support as well as more complex functionality such as multi-threaded programming and object manipulation on remote hosts. Information on the basic technologies can be found here:

J2SE 1.4.2 | J2SE 5.0 | Java SE 6

See Also:

Java SE Internationalization Home Page
Core APIs Forum
The Java Tutorial