# Key Terms

| Term          | Definition                                                                       |
| ------------- | -------------------------------------------------------------------------------- |
| MatchAgent    | The script installed on your site that powers campaign-specific personalization  |
| UTM           | URL tags (e.g., `utm_source=google`) that identify where a visitor came from     |
| CampaignMatch | When UTM rules match and mapped page elements are automatically swapped          |
| Rematch       | A built-in split test that rotates up to 5 copy variants within a CampaignMatch  |
| Variant       | One version of copy within a Rematch (A–E)                                       |
| View          | Any page load where the MatchAgent is present                                    |
| Eligible View | A View where the visitor's UTMs qualify them for personalization                 |
| Referrer      | The domain a visitor came from — used as an optional qualifier alongside UTMs    |
| Conversion    | A tracked action (button click, form success) tied to a CampaignMatch or variant |