Glossary
========

.. glossary::
   :sorted:


   ``.bst`` file
       The configuration for an :term:`Element <Element>`, represented
       in YAML format.


   Artifact
       The output collected after building an :term:`Element`.

       Artifacts can be built from :term:`Sources <Source>`, or pulled from a
       :term:`Remote Cache <Remote Cache>`, if available.

   Artifact name
       The :ref:`name of an artifact <artifact_names>`, which can be used
       in various commands to operate directly on artifacts, without requiring
       the use of a :term:`Project`.

   Cache
       BuildStream leverages various caching techniques in order to avoid
       duplicating work.

       Depending on context, "Cache" might refer to BuildStream's :term:`local
       cache <Local Cache>` or a :term:`Remote Cache <Remote Cache>`.


   Core plugin
       A :term:`Plugin <Plugin>` that is contained in the BuildStream
       package.  These are built-in and don't need to be defined in the
       project configuration.

       See :ref:`plugin documentation <plugins>` for more details on core
       plugins.


   Dependency
       :term:`Elements <Element>` in a BuildStream project can depend
       on other elements from the same project. The element dependent upon is
       called a dependency.

       See :ref:`Dependencies document <format_dependencies>` for more
       details.

   Dependency configuration
       Additional custom YAML configuration which is used to define
       an :term:`Element's <Element>` relationship with it's :term:`Dependency <Dependency>`.

       This is supported on limited :term:`Element <Element>` implementations, and
       each :term:`Element <Element>` defines what configuration it supports.

       See the :ref:`dependency documentation <format_dependencies>` for details
       on dependency configuration.

   Element
       An atom of a :term:`BuildStream project <Project>`. Projects consist of
       zero or more elements.

       During the build process, BuildStream transforms :term:`Sources
       <Source>` and :term:`Dependencies <Dependency>` of an
       element into its output. The output is called an
       :term:`Artifact <Artifact>`.

       Configuration for elements is stored in form of :term:`.bst files
       <.bst file>`. See :ref:`Declaring Elements document <format_basics>`
       for more details on element configurtion.


   External Plugin
       A :term:`Plugin <Plugin>` that is defined in some package other
       than BuildStream.

       External plugins must be declared in :ref:`the project configuration
       <project_plugins>`.

       For a list of known external plugin repositories, see
       :ref:`plugins_external`.


   Junction
       A special kind of :term:`Element <Element>`, that allows you to
       depend on elements from another project.

       See :mod:`Junction reference <elements.junction>` for details on how to
       configure junction elements.

       See :ref:`Junction guide <junction_elements>` for details on how to use
       junction elements.


   Local Cache
       To avoid duplicating work, BuildStream will cache sources, artifacts,
       logs, buildtrees etc. in a local cache directory. If these sources or
       artifacts are needed another time, BuildStream will use them from the
       cache.

       See :ref:`Local cache expiry <config_local_cache>` section of the user
       guide for details on how to configure the local cache.


   Plugin
       BuildStream Plugins define types of :term:`Elements <Element>`
       and :term:`Sources <Source>`. Hence, they come in two distinct
       varities - Element Plugins and Source Plugins.

       BuildStream supports some plugins :term:`out of the box
       <Core plugin>`. It also has support for :term:`third party
       plugins <External Plugin>`.


   Project
       A collection of :term:`Elements <Element>`.

       Elements in a project share some central configuration. See
       :ref:`projectconf` to learn how to configure BuildStream projects.


   Remote Cache
       A server setup for sharing BuildStream :term:`Sources <Source>`
       and/or :term:`Artifacts <Artifact>`.

       See :ref:`cache server documentation <cache_servers>` for details on
       artifact caches.


   Source
       Sources describe the input to the build of an :term:`Element`.

       In general, an element can have zero or more sources. But, certain
       element plugins may restrict the number of allowed sources.

       Sources are defined in the :ref:`Sources <format_sources>` section of
       :term:`Element <Element>` configuration.


   Subproject
       Subprojects are :term:`projects <Project>` which are referred
       to by a :term:`Junction`.


   Workspace
       Workspaces allow building one or more elements using a local, and
       potentially modified, copy of their sources.

       See :ref:`Workspaces guide <developing_workspaces>` for more details on
       how to use workspaces.