JARs can be stored in three different locations in the lib
directory, each
with a different purpose.
JARs in the development
directory are only visible during compile time. Most
of these JARs are already included by the application server or are only useful
for a specific database (i.e., JDBC drivers).
JARs in the global
directory are automatically copied to the application
server's global classpath and are visible by all applications loaded by the
application server.
JARs in the portal
directory are automatically copied to the portal classpath
and are only visible by the portal.