@MikeR00 hey, thanks for your question and welcome to the community!

The “Audience” you have to select, or create, is actually a Google Audience, which is a Google Ads equivalent of a Klaviyo segment. Essentially, a group of people which fulfill the same preset conditions (age, location, page browsed...).

Selecting (or creating) an audience allows information to pass from your retargeting segment on Klaviyo (the one on the left side) to pass onto the lookalike audience in Google (the one that confused you).

You can then use that audience in Google Ads to retarget from Klaviyo campaigns or flows. (e.g. a 10% off email goes out to your connected segment in Klaviyo, then you can find anyone that didn’t interact with this email in your connected Google Audience, and show them an ad to try and convert them that way).

For further reading please refer to this Klaviyo Help article about integrating Klaviyo and Google Ads. 

Happy to chat further!

Thanks @StefanUE , great explanation! Just to add, the audience selection acts like a filter, not a campaign targeter within Google Ads. It ensures only relevant leads based on your criteria reach Klaviyo for nurturing.

Thanks for these replies,  This make more sense now.    Is there any way to pass information from

Google ads →  Klaviyo using out of the box integration? 

or is this only for transferring information from Klaviyo → Google ads ?

@MikeR00 - the out of box integration is meant to transfer data from Klaviyo to Google, but you can i.e. drive leads from Google using Lead Forms in your advertising using a tool like Zapier. The quality of these leads are, according to our data at Ackermann, of quite high value, but can be difficult to scale. 

See more here: https://support.google.com/google-ads/answer/9423234?hl=en