Difference between jar and war in Java

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

Is it only the file extension or is there something more?

From Java Tips: Difference between ear jar and war files:

These files are simply zipped files
using the java jar tool. These files are
created for different purposes. Here
is the description of these files:

-
.jar files: The .jar files contain
libraries, resources and
accessories files like property files.

-
.war files: The war file contains
the web application that can be
deployed on any servlet/jsp
container. The .war file contains jsp,
html, javascript and other files
necessary for the development of web
applications.

Official Sun/Oracle descriptions:

• The J2EETM Tutorial: Web Application Archives

• The Java Archive (JAR) File Format: The Basics

Wikipedia articles:

• WAR file format (Sun)

• JAR file

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