Middleware Question:

The modes of deploymnet are: Stage,No-stage and External
STAGE: The Administration Server first copies the
deployment unit source files to the staging directories of
target servers specified by the Staging Directory Name
attribute.
The target servers then deploy using their local copy of
the

NOSTAGE: The Administration Server does not copy
deployment unit files. Instead, all servers deploy using
the same physical copy of the deployment files, which must
be directly accessible by the Administration Server and
target servers.
With nostage deployments of exploded archive directories,
WebLogic Server automatically detects changes to a
deployment's JSPs or Servlets and refreshes the deployment.
(This behavior can be disabled if necessary.)

EXTERNAL_stage: The Administration Server does not copy
deployment files. Instead, the Administrator must ensure
that deployment files are distributed to the correct
staging directory location before deployment (for example,
by manually copying files prior to deployment).
With external_stage deployments, the Administration Server
requires a copy of the deployment files for validation
purposes. Copies of the deployment files that reside in
target servers' staging directories are not validated
before deployment.