# Glossary

This glossary defines the terms that [Azion Lib](/en/documentation/devtools/azion-lib/) uses in its packages and across its documentation.

| Term              | Definition                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| ----------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| client            | The object a `createClient` function returns, which holds your token and options and exposes the calls of one or more modules. The `azion` package's [createClient](/en/documentation/devtools/azion-lib/client/#createclient) returns a client with one property per module, six in all, and each module also creates its own client. A function called without a client reads the token from `AZION_TOKEN`, as [Module clients and standalone functions](/en/documentation/devtools/azion-lib/client/#module-clients-and-standalone-functions) describes. |
| module            | One Azion Lib library, such as Storage, SQL, or JWT, imported from its own path. The path is a subpath of the `azion` package, such as `azion/purge`, or a scoped package, such as `@aziontech/storage`. The documentation also calls a module a library, and [Client](/en/documentation/devtools/azion-lib/client/#modules) lists the six modules the client reaches.                                                                                                                                                                                      |
| preset            | Bundler settings that a build applies, in one of two senses. The build preset is the `preset` field of `build` in an Azion configuration: a name such as `javascript`, or an `AzionBuildPreset` object, as [Config](/en/documentation/devtools/azion-lib/config/) describes. The unenv preset is the default export of `@aziontech/unenv-preset`, `{ inject, alias, external, polyfill }`, as [unenv preset](/en/documentation/devtools/azion-lib/unenv/) describes.                                                                                        |
| response envelope | The object a module function returns instead of throwing: `data` holds the result on success, and `error` holds `{ message, operation }` on failure. Each module page documents its own form, such as [Storage](/en/documentation/devtools/azion-lib/storage/#response-envelope), where a successful delete returns no `data`. The [AI client](/en/documentation/devtools/azion-lib/ai-client/#response-envelope) fills `error` with a JavaScript `Error`, and the Applications helpers that act on an application itself throw instead.                    |
| scoped package    | A package published under the `@aziontech` npm scope that carries one module on its own, such as `@aziontech/storage`. Seven modules have one: storage, sql, jwt, utils, config, types, and unenv-preset. The other seven ship only in the `azion` package, which receives bug fixes only, and its maintenance ends in December 2026.                                                                                                                                                                                                                       |