Question based on the example from the Tutorial

This is what we get according to the tutorial.

<web-section name="mySection" i18n-name-key="my-section.name" key="my-section" location="my-item-link" weight="1000"> 
    <description key="my-section.description">The mySection Plugin</description>  
    <label key="my-section.label"/> 
  </web-section>
<web-item name="myItem" i18n-name-key="my-item.name" key="my-item" section="system.top.navigation.bar" weight="1000"> 
    <description key="my-item.description">The myItem Plugin</description>  
    <label key="my-item.label"/>  
    <link linkId="my-item-link">deleteMe</link> 
  </web-item>
<web-item name="Atlassian Developer Site" i18n-name-key="atlassian-developer-site.name" key="atlassian-developer-site" section="my-item-link/my-section" weight="1000"> 
    <description key="atlassian-developer-site.description">The Atlassian Developer Site Plugin</description>  
    <label key="atlassian-developer-site.label"/>
    <link linkId="atlassian-developer-site-link">http://developer.atlassian.com/docs</link> 
  </web-item>

What I understand:
Section name - MySection - web section - key=my-section. Location=my-item-link (no link at the time of creation)
The name of the menu is myItem - web-item - we indicate its location section=system.top.navigation.bar (the global menu.)
Menu artifact - Atlassian DevSite -web-item - we indicate to it the location my-item-link/my-section - location and key from web-section

I see a direct connection between the MySection web section. and Web-item Atlassian Dev
But I never indicated the connection between the web item myItem and the other artifacts. How did it all come together into one element?