What's the difference between "Add JARs" and "Add External JARs" in Eclipse?

In a project's Properties page, under "Java Build Path" -> "Libraries" page, I can't figure out what the difference is between the "Add JARs" and "Add External JARs" butt开发者_如何转开发ons.

Add Jar - to include jar files in you build path which are already present in your project.
Add External jar - used to include jar files which are 'outside' your eclipse project workspace folder. They will either be linked or copied.

'Add JARs' is for adding jar files that are in your project. They are referenced relative to the project directories.

'Add External JARs' is for adding jar files that are elsewhere on your filesystem. They are referenced with absolute paths.

Add External jars: are for adding jars from your filesystem. Add Jars: adding jars from with in the same project, once you click on Add jars you will see all the jars from the same project.

Regards, http://javaho.wordpress.com