JAR 组件与 EAR 有何不同? (应用服务器)

how does a JAR component differ from an EAR? (application server)

相对于 EJBJAREAR 文件之间的 distinction 是什么? Glassfish 帮助说:

thufir@doge:~$ 
thufir@doge:~$ GlassFish_Server/bin/asadmin deploy --help

...

       --type
           The packaging archive type of the component that is being deployed.
           Possible values are as follows:

           car
               The component is packaged as a CAR file.

           ear
               The component is packaged as an EAR file.

           ejb
               The component is an EJB packaged as a JAR file.

           osgi
               The component is packaged as an OSGi bundle.

           rar
               The component is packaged as a RAR file.

           war
               The component is packaged as a WAR file.

所以 EJB 可以打包成 JAR 文件?功能上有什么区别?具体来说,EAR 组件可以做什么 JAR 不能?

EAR - Ear 文件主要用于包含完整的企业应用程序。它包含构成特定 Java EE 应用程序的所有组件。企业应用程序定义为 .jar 文件、资源、类 和多个 Web 应用程序

的集合

JAR - Java Archives (JAR) 一个 JAR 文件封装了一个或多个 Java 类、清单和描述符. Jar 文件基本上用于保存 Java 类 的通用库、资源等。此外,JAR 文件是最低级别的存档。 JAR 文件在 Java EE 中用于打包 EJB 和客户端 Java 应用程序。