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drupal - 11.x
=============
Primary tabs
------------
* [11.x](/api/drupal/11.x)
* [10.3.x](/api/drupal/10)
* [9.5.x](/api/drupal/9)
* [8.9.x](/api/drupal/8.9.x)
* [7.x](/api/drupal/7.x)
Welcome to the Drupal API Documentation!
This site is an API reference for Drupal, generated from comments embedded in the source code. More in-depth documentation can be found at [https://www.drupal.org/developing/api](https://www.drupal.org/developing/api).
Here are some topics to help you get started developing with Drupal.
### Essential background concepts
* [Object-oriented conventions used in Drupal](/api/drupal/core%21core.api.php/group/oo_conventions/11.x "PSR-4, namespaces, class naming, and other conventions.")
* [Extending and altering Drupal](/api/drupal/core%21core.api.php/group/extending/11.x "Overview of extensions and alteration methods for Drupal.")
* [Security and best practices](/api/drupal/core%21core.api.php/group/best_practices/11.x "Overview of standards and best practices for developers")
* [Types of information in Drupal](/api/drupal/core%21core.api.php/group/info_types/11.x "Types of information in Drupal.")
### User interface
* [Menu entries, local tasks, and other links](/api/drupal/core%21lib%21Drupal%21Core%21Menu%21menu.api.php/group/menu/11.x "Define the navigation menus, local actions and tasks, and contextual links.")
* [Routing API and page controllers](/api/drupal/core%21lib%21Drupal%21Core%21Routing%21routing.api.php/group/routing/11.x "Route page requests to code based on URLs.")
* [Forms](/api/drupal/core%21core.api.php/group/form_api/11.x "Describes how to generate and manipulate forms and process form submissions.")
* [Blocks](/api/drupal/core%21modules%21block%21block.api.php/group/block_api/11.x "Information about the classes and interfaces that make up the Block API.")
* [Ajax](/api/drupal/core%21core.api.php/group/ajax/11.x "Overview for Drupal's Ajax API.")
### Storing and retrieving data
* [Entities](/api/drupal/core%21lib%21Drupal%21Core%21Entity%21entity.api.php/group/entity_api/11.x "Describes how to define and manipulate content and configuration entities.")
* [Fields](/api/drupal/core%21modules%21field%21field.module/group/field/10 "Attaches custom data fields to Drupal entities.")
* [Configuration API](/api/drupal/core%21core.api.php/group/config_api/11.x "Information about the Configuration API.")
* [State API](/api/drupal/core%21core.api.php/group/state_api/11.x "Information about the State API.")
* [Views](/api/drupal/core%21modules%21views%21views.api.php/group/views_overview/11.x "Overview of the Views module API")
* [Database abstraction layer](/api/drupal/core%21lib%21Drupal%21Core%21Database%21database.api.php/group/database/11.x "Allow the use of different database servers using the same code base.")
### Other essential APIs
* [Plugins](/api/drupal/core%21core.api.php/group/plugin_api/11.x "Using the Plugin API")
* [Services and the Dependency Injection Container](/api/drupal/core%21core.api.php/group/container/11.x "Overview of the Dependency Injection Container and Services.")
* [Events](/api/drupal/core%21core.api.php/group/events/11.x "Overview of event dispatch and subscribing")
* [Internationalization](/api/drupal/core%21lib%21Drupal%21Core%21Language%21language.api.php/group/i18n/11.x "Internationalization and translation")
* [Caching](/api/drupal/core%21core.api.php/group/cache/11.x "Information about the Drupal Cache API")
* [Utility classes and functions](/api/drupal/core%21core.api.php/group/utility/11.x "Overview of utility classes and functions for developers.")
* [User accounts, permissions, and roles](/api/drupal/core%21core.api.php/group/user_api/11.x "API for user accounts, access checking, roles, and permissions.")
* [Render API](/api/drupal/core%21lib%21Drupal%21Core%21Render%21theme.api.php/group/theme_render/11.x "Overview of the Theme system and Render API.")
* [Theme system](/api/drupal/core%21lib%21Drupal%21Core%21Render%21theme.api.php/group/themeable/11.x "Functions and templates for the user interface that themes can override.")
* [Update API](/api/drupal/core%21lib%21Drupal%21Core%21Extension%21module.api.php/group/update_api/11.x "Updating minor versions of modules")
* [Migration](/api/drupal/core%21modules%21migrate%21migrate.api.php/group/migration/11.x "Overview of the Migrate API, which migrates data into Drupal.")
### Additional topics
* [Batch API](/api/drupal/core%21includes%21form.inc/group/batch/11.x "Creates and processes batch operations.")
* [Queue API](/api/drupal/core%21core.api.php/group/queue/11.x "Queue items to allow later processing.")
* [Typed Data](/api/drupal/core%21core.api.php/group/typed_data/11.x "API for describing data based on a set of available data types.")
* [Automated tests](/api/drupal/core%21core.api.php/group/testing/11.x "Overview of PHPUnit and Nightwatch automated tests.")
* [PHP Runtime Assert Statements](/api/drupal/core%21core.api.php/group/php_assert/11.x "Use of the assert() statement in Drupal.")
* [Integrating third-party applications](/api/drupal/core%21core.api.php/group/third_party/11.x "Integrating third-party applications using REST and related operations.")
### Further information
* [Examples project (sample modules)](https://www.drupal.org/project/examples)
* [API change notices](https://www.drupal.org/list-changes)
* [Drupal API longer references](https://www.drupal.org/docs/drupal-apis)
* * *
**Buggy or inaccurate documentation?** Please [file an issue](https://drupal.org/node/add/project-issue/drupal?component=documentation&categories=2&version=11.x-dev&body=API%20page%3A%20https%3A//api.drupal.org/api/drupal/11.x%0A%0AEnter%20a%20descriptive%20title%20%28above%29%2C%20then%20describe%20the%20problem%20you%20have%20found%3A%0A). Need [support](https://drupal.org/support)? Need help programming? Connect with the [Drupal community](https://drupal.org/community).
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* [Namespaces](/api/drupal/namespaces/11.x)
* [Deprecated](/api/drupal/deprecated/11.x)
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* [Elements](/api/drupal/elements/11.x)