War files specified Web Application Archive and jar
files contain java class files as a library and EAR
files specified Enterprise Archive.
Ear files contain any application file  for j2ee
framework such as war  file, jar  files, ejb class files
and other j2ee files, otherwise war files include only
web files such as images(gif, jpg, ...)
, html, jsp, xml, css , java class files.
A ear file may contains some war files.This extensions
are standards of j2ee for deploying and packaging
applications. All of standard j2ee application
servers(such as Bea Weblogic or IBM WebSphere)
recognize j2ee web applications with war files and
enterprise applications with ear files and manage your
j2ee application with these extensions.