What occurs when auto-tagging is enabled?
- A Google click ID is appended to all landing page URLs
- A label is added to all Google Ads campaigns
- A scheduled edit is created for all Google Ads campaigns
- A Google Click ID is reported in the budget pacing report
Auto-tagging will attach the “Google Click Identifier” (GCLID) parameter to the URL your customers click, and that will help you tell which ad was clicked for each visit to your site.
Read more here: https://support.google.com/searchads/answer/1752125