tar, jar, war, ear, sar files
Many file have extensions ending in "a r".
It's because the "ar" stands for archive, and it's such
a reasonable way of naming file that the original tar
which stands for tape archive was picked up by Sun and
the Java community and transmuted into other file
formats.
tar - tape archive
jar - java archive
war - web application archive
ear - enterprise archive
sar - service archive
war and ear are jar files, created with the jar
utility. In fact, they're a subtype of jar files with
the data they contain being in a specific file and
directory stucture. In other words, the arrangment of
files within a war is such that the file and its
contents are suitable for deployment as a webapp under
a container such as Apache Tomcat, and the arrangement
of files within a ear is such that it's an Enterprise
Archive such as you would use under JBoss, etc.


Can you tell us what is the exact thing which you want
to be done?