You’re seeking an ad format to support influencing consideration for your brand. You’d also like the ad to automatically adjusts its size, appearance, and format to fit available ad spaces and better fit content users came to see. Which ad format suits these needs?
Standard image ads
Responsive ads automatically adjust their size, appearance, and format to fit available ad spaces. With text and images you enter, AdWords automatically generates your ad as ad spaces become available.
Read more here: //support.google.com/adwords/answer/7005917