How is conversion tracking implemented (cookie, tag, UTM)?

Conversion tracking generally relies on three components.

Cookies. These store a session identifier so that the system knows which user completed the action after clicking from an email.

Tags. JavaScript tags fire events that record actions such as purchases or signups.

UTM (Urchin Tracking Module) parameters. These pass campaign level identifiers to analytics tools so you can attribute the action to a specific email.

Together they function like a chain of lantern signals guiding the ship from email to website to purchase without losing sight of which journey began with which message.