The application client container runs on the client machine, and is the gateway between the client application and the Java EE server components that the client uses.

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The application client container runs on the client machine, and is the gateway between the client application and the Java EE server components that the client uses.

If the 'application client container runs on the client machine', then it seems that a (Java EE) 'client application' does not connect directly to a Java EE server at all, so the usage Port that *Client_Application inherited from the more general JavaEE *Client would seem to be invalid for Java EE application clients (although it does seem valid for the generic JavaEE client, as indicated by the related
source text «wrapper» Components shown).

It could act as 'the gateway between the client application and the Java EE server components' by in fact acting as a client to the Java EE server "on behalf of" the application client, so *Container_ApplicationClient has tentatively been given a usage Port to the Java EE *Serve Interface.

It seems the way 'that the client uses', and the way the application client container access, the Java EE server components is indirect and networked.

This is clearer in the next diagram, which shows (hybrid) connected composite structures ("systems engineering view"), rather than the associative "interface dependency wiring" architectural view.