Conversion tracking is the practice of measuring when a desired action — a purchase, a form submission, a signup — occurs as a result of a marketing campaign, typically via a tracking tag or pixel embedded on the relevant page.
Conversion tracking is foundational to marketing measurement, but it fails silently: a tag can stop firing without any visible symptom other than data that looks a little soft, which is easy to attribute to the campaign underperforming rather than to a technical failure. Verifying tracking is actually working — not just configured — is a distinct, necessary check separate from configuring it in the first place.