# Glossary

The pages of this section use the terms below in the sense [Edge Pulse](/en/documentation/platform/edge-pulse/) gives them.

| Term                      | Definition                                                                                                                                                                                                                                                                                                                                                                                          |
| ------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| Default Tag               | One of the two forms of the Edge Pulse JavaScript tag that Azion Console serves. It waits for the page loading event to complete, then downloads and runs the RUM Client, so that event is not interrupted. For where it goes in the page, refer to [Edge Pulse JavaScript tag](/en/documentation/platform/edge-pulse/javascript-tag/).                                                             |
| Edge Pulse JavaScript tag | The script you add to a page so Edge Pulse measures it. Azion Console serves it in two forms, the **Default Tag** and the **Pre-loading Tag**, and one tag covers one page. For what it collects and which browser settings it respects, refer to [Edge Pulse JavaScript tag](/en/documentation/platform/edge-pulse/javascript-tag/).                                                               |
| Pre-loading Tag           | One of the two forms of the Edge Pulse JavaScript tag that Azion Console serves, for a page whose Content Security Policy settings prevent the use of inline JavaScript. It executes before the load event fires. To choose between the two tags, refer to [Edge Pulse JavaScript tag](/en/documentation/platform/edge-pulse/javascript-tag/).                                                      |
| pulseEvents               | The dataset that holds the Edge Pulse measurements in the Real-Time Events GraphQL API, and the one to query. The older `edgePulseEvents` is deprecated and the schema says so. For its fields, refer to [Real-Time Events GraphQL API fields](/en/documentation/devtools/graphql/gql-real-time-events-fields/).                                                                                    |
| RUM Client                | The component the Edge Pulse JavaScript tag downloads and runs in the visitor's browser, and what performs the measurements. The **Default Tag** waits for the page loading event to complete before downloading it. For which tag downloads it when, refer to [Edge Pulse JavaScript tag](/en/documentation/platform/edge-pulse/javascript-tag/).                                                  |
| test                      | One measurement a visitor's browser performs against addresses of Azion's distributed infrastructure. Edge Pulse repeats the test at a fixed interval for each visitor, and the results go to Azion's processing servers. For the number of addresses one test covers and the interval between tests, refer to [How Edge Pulse works](/en/documentation/platform/edge-pulse/how-it-works/).         |
| visitor identifier        | The value that tells one visitor's measurements from another's. Edge Pulse generates it with the UUID4 algorithm, the random form of the universally unique identifier, and keeps it in the local storage of the browser. For how the `navigator.doNotTrack` setting changes how long the value lives, refer to [Edge Pulse JavaScript tag](/en/documentation/platform/edge-pulse/javascript-tag/). |