# Amazon Mechanical Turk API Reference
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This is the *Amazon Mechanical Turk API Reference*. This guide provides detailed information about Amazon Mechanical Turk operations, data structures, and parameters. The major sections of this guide are described in the following table. 

Amazon Mechanical Turk is a web service that provides an on-demand, scalable, human workforce to complete jobs that humans can do better than computers, for example, recognizing objects in photos. For more information about this product go to the Amazon Mechanical Turk [website](http://www.mturk.com). 

**Important**  
If you do not add a CORS configuration to the S3 buckets that contain your image input data, HITs that you create using those input images will fail. To learn more, see [CORS Configuration Requirement](https://docs.aws.amazon.com/AWSMechTurk/latest/AWSMechanicalTurkRequester/MturkCorsConfig.html).


|  |  | 
| --- |--- |
|  [Operations](ApiReference_OperationsArticle.md)  | Alphabetical list of all Amazon Mechanical Turk operations. | 
|  [Data Structure Schema Locations](ApiReference_SchemaLocationArticle.md)  | Links to Amazon Mechanical Turk data structure schemas. | 
|  [Question and Answer Data](ApiReference_QuestionAnswerDataArticle.md)  | Description of question and answer data that Amazon Mechanical Turk passes between Requesters and Workers. | 
|  [Data Structures](ApiReference_DataStructuresArticle.md)  | Alphabetical list of all Amazon Mechanical Turk data structures. | 
|  [Review Policies](ApiReference_ReviewPoliciesArticle.md)  | Description of Amazon Mechanical Turk Review Policies. | 
|  [Managing Notifications](ApiReference_NotificationReceptorAPIArticle.md)  | Description of how Amazon Mechanical Turk sends notification messages to your application. |