Audience Availability

[87DavidAB]

I understand that for AAM audiences, the audience becomes actionable "next page".

Audience creation options in Adobe Experience Cloud

If I have an activity live on "page ABC" which uses AAM audiences to determine which variation a user should see, when exactly does the audience become actionable?

For example, does the first page hit need to be on "page ABC" (where the activity is) or can it be anywhere on my site?