Google is phasing out 3rd party cookies. This make’s tracking consumer activity across devices difficult. To improve conversion tracking, Google is shifting over to "Enhanced Conversions."
In Google’s words:
"Enhanced Conversions is a feature that can improve the accuracy of your conversion measurement. It supplements your existingconversion tags by sending hashed first-party conversion data from your website to Google in a privacy-safe way."
When customers complete a conversion on your website, you may receive first-party customer data such as an email address, name, home address, and/or phone number. This data can be captured in your conversion tracking tags, hashed, sent to Google in its hashed form, and then used to enhance your conversion measurement.
Enhanced conversions improve the accuracy of your conversion measurement and are the key to unlocking more powerful bidding strategies. They supplement your existing conversion tags by sending hashed first-party conversion data from your website to Google in a privacy-safe way. This feature uses a secure one-way hashing algorithm called SHA256 on your first-party customer data, such as email addresses, before sending it to Google. In other words, it collects customer data and then sends hashed user information to Google so that Google can match it against signed-in Google accounts.