Ads live under flights and contain information about the creative that will be shown, as well as any additional targeting details that live at the ad-level. An "ad" in Kevel is different from a "creative", as an "ad" refers to creatives that are specifically linked to a flight and thus have targeting and are eligible to serve.
Note that internally ads are sometimes called "Creative Flight Maps".
The advertiser of the creative must match the advertiser of the flight when creating or updating an ad.
Learn more about ads here.
"Creative Flight Maps" refers to the tying of a creative to a flight.