.war vs .ear file

Q：

What is the difference between a .war and .ear file?

A：

In J2EE application modules are packaged as EAR, JAR and WAR based on their functionality

JAR: EJB modules which contains enterprise java beans class files and EJB deployment descriptor are packed as JAR files with .jar extenstion

WAR: Web modules which contains Servlet class files,JSP FIles,supporting files, GIF and HTML files are packaged as JAR file with .war (web achive) extension

EAR: All above files (.jar and .war) are packaged as JAR file with .ear (enterprise archive) extension and deployed into Application Server.