IIS Session Timeout vs ASP.NET Session Timeout

In IIS 6 (and other versions too afaik), there is a Session Timeout setting in Properties -> Home Directory Tab -> Configuration button -> Options tab. Looks like this:

And in the ASP.NET web.config there is a SessionState setting, looks like this:

<system.web>
    <sessionState timeout="120" />
    <!-- etc .. -->
</system.web>

Are they, by any chance, related? Do they set the same thing, or different things?

They are not the same. The IIS session timeout is for clasic ASP pages. The web.config one is for asp.net.