# The Definitive Guide to Yii 22.0 > Table of contents of the guide: getting started, application structure, requests, key concepts, databases, forms, output, security, caching, REST and testing. This tutorial is released under the [Terms of Yii Documentation](https://www.yiiframework.com/doc/terms/). All Rights Reserved. 2014 (c) Yii Software LLC. ## Introduction - [About Yii](/docs/guide/intro-yii/index.md) - [Upgrading from Version 1.1](/docs/guide/intro-upgrade-from-v1/index.md) ## Getting Started - [What do you need to know](/docs/guide/start-prerequisites/index.md) - [Installing Yii](/docs/guide/start-installation/index.md) - [Running Applications](/docs/guide/start-workflow/index.md) - [Saying Hello](/docs/guide/start-hello/index.md) - [Working with Forms](/docs/guide/start-forms/index.md) - [Working with Databases](/docs/guide/start-databases/index.md) - [Generating Code with Gii](/docs/guide/start-gii/index.md) - [Looking Ahead](/docs/guide/start-looking-ahead/index.md) ## Application Structure - [Application Structure Overview](/docs/guide/structure-overview/index.md) - [Entry Scripts](/docs/guide/structure-entry-scripts/index.md) - [Applications](/docs/guide/structure-applications/index.md) - [Application Components](/docs/guide/structure-application-components/index.md) - [Controllers](/docs/guide/structure-controllers/index.md) - [Models](/docs/guide/structure-models/index.md) - [Views](/docs/guide/structure-views/index.md) - [Modules](/docs/guide/structure-modules/index.md) - [Filters](/docs/guide/structure-filters/index.md) - [Widgets](/docs/guide/structure-widgets/index.md) - [Assets](/docs/guide/structure-assets/index.md) - [Extensions](/docs/guide/structure-extensions/index.md) ## Handling Requests - [Request Handling Overview](/docs/guide/runtime-overview/index.md) - [Bootstrapping](/docs/guide/runtime-bootstrapping/index.md) - [Routing and URL Creation](/docs/guide/runtime-routing/index.md) - [Requests](/docs/guide/runtime-requests/index.md) - [Responses](/docs/guide/runtime-responses/index.md) - [Sessions and Cookies](/docs/guide/runtime-sessions-cookies/index.md) - [Handling Errors](/docs/guide/runtime-handling-errors/index.md) - [Logging](/docs/guide/runtime-logging/index.md) ## Key Concepts - [Components](/docs/guide/concept-components/index.md) - [Properties](/docs/guide/concept-properties/index.md) - [Events](/docs/guide/concept-events/index.md) - [Behaviors](/docs/guide/concept-behaviors/index.md) - [Configurations](/docs/guide/concept-configurations/index.md) - [Aliases](/docs/guide/concept-aliases/index.md) - [Class Autoloading](/docs/guide/concept-autoloading/index.md) - [Service Locator](/docs/guide/concept-service-locator/index.md) - [Dependency Injection Container](/docs/guide/concept-di-container/index.md) ## Working with Databases - [Database Access Objects](/docs/guide/db-dao/index.md): Connecting to a database, basic queries, transactions, and schema manipulation - [Query Builder](/docs/guide/db-query-builder/index.md): Querying the database using a simple abstraction layer - [Active Record](/docs/guide/db-active-record/index.md): The Active Record ORM, retrieving and manipulating records, and defining relations - [Migrations](/docs/guide/db-migrations/index.md): Apply version control to your databases in a team development environment - [Sphinx](https://www.yiiframework.com/extension/yiisoft/yii2-sphinx/doc/guide) - [Redis](https://www.yiiframework.com/extension/yiisoft/yii2-redis/doc/guide) - [MongoDB](https://www.yiiframework.com/extension/yiisoft/yii2-mongodb/doc/guide) - [ElasticSearch](https://www.yiiframework.com/extension/yiisoft/yii2-elasticsearch/doc/guide) ## Getting Data from Users - [Creating Forms](/docs/guide/input-forms/index.md) - [Validating Input](/docs/guide/input-validation/index.md) - [Uploading Files](/docs/guide/input-file-upload/index.md) - [Collecting Tabular Input](/docs/guide/input-tabular-input/index.md) - [Getting Data for Multiple Models](/docs/guide/input-multiple-models/index.md) - [Extending ActiveForm on the Client Side](/docs/guide/input-form-javascript/index.md) ## Displaying Data - [Data Formatting](/docs/guide/output-formatting/index.md) - [Pagination](/docs/guide/output-pagination/index.md) - [Sorting](/docs/guide/output-sorting/index.md) - [Data Providers](/docs/guide/output-data-providers/index.md) - [Data Widgets](/docs/guide/output-data-widgets/index.md) - [Working with Client Scripts](/docs/guide/output-client-scripts/index.md) - [Theming](/docs/guide/output-theming/index.md) ## Security - [Security Overview](/docs/guide/security-overview/index.md) - [Authentication](/docs/guide/security-authentication/index.md) - [Authorization](/docs/guide/security-authorization/index.md) - [Working with Passwords](/docs/guide/security-passwords/index.md) - [Cryptography](/docs/guide/security-cryptography/index.md) - [Auth Clients](https://www.yiiframework.com/extension/yiisoft/yii2-authclient/doc/guide) - [Best Practices](/docs/guide/security-best-practices/index.md) ## Caching - [Caching Overview](/docs/guide/caching-overview/index.md) - [Data Caching](/docs/guide/caching-data/index.md) - [Fragment Caching](/docs/guide/caching-fragment/index.md) - [Page Caching](/docs/guide/caching-page/index.md) - [HTTP Caching](/docs/guide/caching-http/index.md) ## RESTful Web Services - [Quick Start](/docs/guide/rest-quick-start/index.md) - [Resources](/docs/guide/rest-resources/index.md) - [Controllers](/docs/guide/rest-controllers/index.md) - [Filtering Collections](/docs/guide/rest-filtering-collections/index.md) - [Routing](/docs/guide/rest-routing/index.md) - [Response Formatting](/docs/guide/rest-response-formatting/index.md) - [Authentication](/docs/guide/rest-authentication/index.md) - [Rate Limiting](/docs/guide/rest-rate-limiting/index.md) - [Versioning](/docs/guide/rest-versioning/index.md) - [Error Handling](/docs/guide/rest-error-handling/index.md) ## Development Tools - [Debug Toolbar and Debugger](https://www.yiiframework.com/extension/yiisoft/yii2-debug/doc/guide) - [Generating Code using Gii](https://www.yiiframework.com/extension/yiisoft/yii2-gii/doc/guide) - [Generating API Documentation](https://www.yiiframework.com/extension/yiisoft/yii2-apidoc) ## Testing - [Testing Overview](/docs/guide/test-overview/index.md) - [Testing environment setup](/docs/guide/test-environment-setup/index.md) - [Unit Tests](/docs/guide/test-unit/index.md) - [Functional Tests](/docs/guide/test-functional/index.md) - [Acceptance Tests](/docs/guide/test-acceptance/index.md) - [Fixtures](/docs/guide/test-fixtures/index.md) ## Special Topics - [Advanced Project Template](https://www.yiiframework.com/extension/yiisoft/yii2-app-advanced/doc/guide) - [Building Application from Scratch](/docs/guide/tutorial-start-from-scratch/index.md) - [Console Commands](/docs/guide/tutorial-console/index.md) - [Core Validators](/docs/guide/tutorial-core-validators/index.md) - [Docker](/docs/guide/tutorial-docker/index.md) - [Internationalization](/docs/guide/tutorial-i18n/index.md) - [Mailing](/docs/guide/tutorial-mailing/index.md) - [Performance Tuning](/docs/guide/tutorial-performance-tuning/index.md) - [Shared Hosting Environment](/docs/guide/tutorial-shared-hosting/index.md) - [Template Engines](/docs/guide/tutorial-template-engines/index.md) - [Working with Third-Party Code](/docs/guide/tutorial-yii-integration/index.md) - [Using Yii as a micro framework](/docs/guide/tutorial-yii-as-micro-framework/index.md) ## Widgets - [GridView](https://www.yiiframework.com/doc-2.0/yii-grid-gridview.html) - [ListView](https://www.yiiframework.com/doc-2.0/yii-widgets-listview.html) - [DetailView](https://www.yiiframework.com/doc-2.0/yii-widgets-detailview.html) - [ActiveForm](https://www.yiiframework.com/doc-2.0/guide-input-forms.html#activerecord-based-forms-activeform) - [Pjax](https://www.yiiframework.com/doc-2.0/yii-widgets-pjax.html) - [Menu](https://www.yiiframework.com/doc-2.0/yii-widgets-menu.html) - [LinkPager](https://www.yiiframework.com/doc-2.0/yii-widgets-linkpager.html) - [LinkSorter](https://www.yiiframework.com/doc-2.0/yii-widgets-linksorter.html) - [Bootstrap Widgets](https://www.yiiframework.com/extension/yiisoft/yii2-bootstrap/doc/guide) - [jQuery UI Widgets](https://www.yiiframework.com/extension/yiisoft/yii2-jui/doc/guide) ## Helpers - [Helpers Overview](/docs/guide/helper-overview/index.md) - [ArrayHelper](/docs/guide/helper-array/index.md) - [Html](/docs/guide/helper-html/index.md) - [Json](/docs/guide/helper-json/index.md) - [Url](/docs/guide/helper-url/index.md)