> For the complete documentation index, see [llms.txt](https://docs.drizz.dev/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.drizz.dev/reference/glossary.md).

# Glossary

The vocabulary used across these docs and in the product UI, alphabetically.

|               |                                                                   |
| ------------- | ----------------------------------------------------------------- |
| **Covers**    | Terms used throughout the documentation and in the product UI     |
| **Naming**    | Chat is also referred to as Fathom in older material              |
| **Watch out** | "Memory" names two different things. Check which one a page means |

<table data-search="false"><thead><tr><th>Term</th><th>Definition</th></tr></thead><tbody><tr><td><strong>AUT</strong></td><td>App under test — the app Drizz is driving</td></tr><tr><td><strong>Blocker rule</strong></td><td>A Memory rule that dismisses a known popup automatically. One rule carries one action</td></tr><tr><td><strong>Cached step</strong></td><td>A step Drizz has resolved on this screen before and replays without calling Vision AI. Lowest-cost step category</td></tr><tr><td><strong>Chat</strong></td><td>The panel that generates a test from a plain-English description. Referred to as <strong>Fathom</strong> in older material</td></tr><tr><td><strong>Dataset</strong></td><td>Named values bound to a test plan at run time and referenced in a script as <code>{{var}}</code>. Nesting is limited to two levels</td></tr><tr><td><strong>Desktop app</strong></td><td>The Drizz application installed locally to author tests and run them on a connected device</td></tr><tr><td><strong>Drizz device cloud</strong></td><td>The hosted devices a test plan runs on. One of three run targets, with local and private devices</td></tr><tr><td><strong>DT</strong></td><td>Drizz Token — the unit Drizz meters usage in, deducted per step. Current rates are on your organization's billing page</td></tr><tr><td><strong><code>execution_id</code></strong></td><td>The identifier returned when a test plan is triggered over the API. Confirms a run started. Not pollable</td></tr><tr><td><strong>Lockable pool</strong></td><td>A dataset whose rows are leased exclusively to one run at a time. A run waits when the pool is fully leased</td></tr><tr><td><strong><code>MAP_ACTION</code></strong></td><td>A grid- and coordinate-based gesture, for elements Vision AI cannot target normally. Pinch and zoom are limited to specific Android emulator types</td></tr><tr><td><strong>Memory</strong></td><td>Org-level app context and blocker rules, applied before a run starts. Unrelated to <code>Store</code> and <code>SET</code> variables</td></tr><tr><td><strong>Module</strong></td><td>A reusable block of steps, defined once and invoked with <code>CALL</code>. Takes parameters, passed by value</td></tr><tr><td><strong>Private device</strong></td><td>A device reserved for a single organization</td></tr><tr><td><strong>Registered app</strong></td><td>An app binary uploaded to Drizz, available to test plans and to Memory. Capped at 500 MB</td></tr><tr><td><strong>Self-healing</strong></td><td>Automatic repair of a failed step, a limited number of times per run. Healed steps are badged in the report</td></tr><tr><td><strong><code>SET</code></strong></td><td>Assigns a value to a variable inside a script</td></tr><tr><td><strong><code>Store</code></strong></td><td>Captures a value from the current screen into a variable</td></tr><tr><td><strong>Test plan</strong></td><td>A set of tests plus how and where they run — devices, concurrency, app version, dataset binding</td></tr><tr><td><strong>Variable</strong></td><td>A named value used inside a script. Produced by <code>Store</code>, <code>SET</code>, dataset values or placeholders</td></tr><tr><td><strong>Vision AI</strong></td><td>The layer that reads the screen and locates elements without selectors or an SDK</td></tr><tr><td><strong>Wallet</strong></td><td>An organization's DT balance, shared org-wide. States are Healthy, Low and Blocked</td></tr></tbody></table>

## Terms with two names

| Term   | Also called | Rule in these docs                                                                                                      |
| ------ | ----------- | ----------------------------------------------------------------------------------------------------------------------- |
| Chat   | Fathom      | Write **Chat**. Fathom in older material means Chat                                                                     |
| Memory | —           | **Memory** is the org-level app context and blocker rules only. Runtime values from `Store` and `SET` are **variables** |

## Next

* [Command index](/writing-tests/command-index.md) — every command, one table
* [Known limitations](/reference/known-limitations.md) — what Drizz doesn't do
* [Which variable do I use?](/writing-tests/which-variable.md) — Store vs SET vs dataset vs placeholder

***

*Last updated: 6 August 2026*