ant create-component and websiteId

[Christopher Snow]

When I create a component with "ant create-component", the web.xml contains:
   <context-param>
       <param-name>webSiteId</param-name>
       <param-value>EXAMPLE</param-value>
       <description>A unique ID used to look up the WebSite 
entity</description>
   </context-param>

What is the main purpose for the webSiteId?

Many thanks in advance,

Chris