A prospect can be in or out of a campaign.
When a prospects is in a campaign and the campaign is running, it means they're going through the steps of that campaign.
Out of campaign
When a prospect is out of a campaign it means they were previously in that campaign but not in anymore. A prospect can be out of a campaign for 4 different reasons:
Prospects for whom the campaign was stopped because they performed an action that triggered an exit.
Examples: they replied, clicked on a link, have been qualified or have been converted.
Prospects who went through all the steps of the campaign and did not trigger an exit event. They basically received all the steps of the campaign and nothing happened.
Prospects for whom the campaign was stopped manually. The prospect has been manually removed from the campaign by a user of your account.
The prospect's for whom the email bounced. When that happens, our system will automatically remove the prospect from the campaign.