A J2EE library is a stand-alone EJB or Web Application module, multiple EJB or Web Application modules packaged in an Enterprise Application (EAR), or a single plain JAR file that is registered with the J2EE application container upon deployment. After the library has been installed and started, other deployed modules can reference the library.
Libraryentry in the Type column.
The name of the J2EE library is always followed by a version of
Specification identifies the version number
of the specification (for example, the J2EE specification version)
to which a library or package conforms and
Implementation Identifies the version number
of the actual code implementation for the library or package. This
versioning of J2EE libraries enables referencing applications to
specify a required minimum version of the library to use, or an
exact, required version.