In other words..
a.) Google Audience Match: A way to market to know customer "Using information that your customers have shared with you, Customer Match will target ads to those customers and other customers like them"
b.) Google Ads: Unknown visitor with a assigned ID (GAID, IDFA etc..) as identifier
Let's say you have mobile apps data with IDFA/GAID in a data set, you could create audience based on these and share it to google ads for marketing activation.
On the other hand, for logged in users of your site.. create an audience of "quote created" and send email/hashed email to Google Audience Match for your marketing activation
Hope that helps!