# Audiences & delivery

URL: https://docs.ablyft.com/guides/audiences-and-delivery/

> Choose where an experiment runs, who takes part and how visitors are distributed.



Whether a visitor sees an experiment depends on a few questions that ABlyft answers one after the other:

1. **Where?** The visitor must be on a [page](https://docs.ablyft.com/guides/audiences-and-delivery/pages/) that is attached to the experiment.
2. **On which site?** If the experiment is restricted to [environments](https://docs.ablyft.com/guides/audiences-and-delivery/environments/),
   one of them must apply.
3. **Who?** The visitor must match the [audiences](https://docs.ablyft.com/guides/audiences-and-delivery/audiences/) of the experiment. Without
   audiences, everybody is included.
4. **Only this experiment?** If the experiment belongs to an
   [exclusion group](https://docs.ablyft.com/guides/experiments/exclusion-groups/), the visitor must be assigned to it and not to another
   experiment of the group.
5. **How many?** The [traffic allocation](https://docs.ablyft.com/guides/audiences-and-delivery/traffic-allocation/) decides whether the visitor
   takes part and which variation they get.

Pages, audiences and environments are defined once per project and can be reused in many experiments. Developers find
the exact order in which the snippet runs these checks in the
[snippet sequence](https://docs.ablyft.com/developers/installation/snippet-sequence/).

- [Pages & URL targeting](https://docs.ablyft.com/guides/audiences-and-delivery/pages/): Where an experiment runs.
- [Audiences](https://docs.ablyft.com/guides/audiences-and-delivery/audiences/): Who sees an experiment.
- [Traffic allocation](https://docs.ablyft.com/guides/audiences-and-delivery/traffic-allocation/): Distribute visitors across variations.
- [Environments](https://docs.ablyft.com/guides/audiences-and-delivery/environments/): Run the same project in several environments.
- [Exclusion groups](https://docs.ablyft.com/guides/experiments/exclusion-groups/): Keep experiments mutually exclusive.