| Log Type       | Description                                                                 | Example Use Case                                                           |
|----------------|-----------------------------------------------------------------------------|---------------------------------------------------------------------------|
| **Impression** | Records each time an impression is generated. Includes metadata like creative, campaign, and placement. | Tracking ad delivery                                                       |
| **Click**      | Captures when a user clicks on an ad. Includes timestamp, device info, and associated impression metadata. | Analyze click-through rates (CTR), user engagement, or measure ad creative performance. |
| **Conversion**  | Logged when a conversion event is attributed to a prior ad interaction (e.g. click or view). See [Attribution](https://dev.kevel.com/docs/attribution-overview). | Track attribute sales that occur from ads                                  |
| **Custom Event** | Tracks custom events (e.g. add to cart, add to wish list).                | Track additional engagement metrics associated to ads                     |
| **Request**    | Logs every ad request made to Kevel's Decision API                        | Gain visibility in to Ad Decision Requests sent to Kevel                  |
| **Decision**   | Contains detailed information for each placement you've asked Kevel to fill via Kevel's Ad Decision API | Gain visibility in to Ad Decision Requests sent to Kevel, and for monitoring fill-rate in combination with Selection logs |
| **Auction**    | Records bidding data for each auction that occurs, including all bids and their projected values. | Audit pricing and bidding logic, or build advanced bidding and auction health metrics |
| **Selection**  | Records final ad selections made by Kevel                                   | Gain further visibility in to each ad that Kevel has selected to serve.   |
| **UserDB**     | Logs events related to user data writes and updates to Kevel’s UserDB (e.g. segmentation updates). | Monitor updates made to UserDB.                                          |