The Java Archive (JAR) file format enables you to bundle multiple files into a single archive file. Typically a JAR file contains the class files and auxiliary resources associated with applets and applications.
The JAR file format provides many benefits:
• Security: You can digitally sign the contents of a JAR file. Users who recognize your signature can then optionally grant your software security privileges it wouldn’t otherwise have.
• Decreased download time: If your applet is bundled in a JAR file, the applet’s class files and associated resources can be downloaded to a browser in a single HTTP transaction without the need for opening a new connection for each file.
• Compression: The JAR format ...