> ## Documentation Index
> Fetch the complete documentation index at: https://docs.abbyy.com/llms.txt
> Use this file to discover all available pages before exploring further.

# API Reference

<Warning>
  The API Reference section applies to Linux, macOS, and Windows.
</Warning>

This section contains the description of ABBYY FineReader Engine API which helps you to:

* Use main functions and global settings:
  * [Functions](/fine-reader/engine/api-reference/functions)
  * [Engine Object (IEngine Interface)](/fine-reader/engine/api-reference/engine-object-iengine-interface)
  * [Engine Loaders](/fine-reader/engine/api-reference/engine-loaders) (Win)
* [Manage your licenses](/fine-reader/engine/api-reference/license-related-objects)
* [Work with images](/fine-reader/engine/api-reference/image-related-objects) and prepare them for processing
* Tune the processing settings:
  * [languages and dictionary words](/fine-reader/engine/api-reference/language-related-objects)
  * [parameters](/fine-reader/engine/api-reference/parameter-objects)
  * [auxiliary settings](/fine-reader/engine/api-reference/supplementary-objects-and-methods)
* Process the documents:
  * via [FRDocument and document-related objects](/fine-reader/engine/api-reference/document-related-objects)
  * or via [BatchProcessor](/fine-reader/engine/api-reference/batch-processor) receiving images from queue (Windows and Linux)
* Get the results:
  * [details of the page layout](/fine-reader/engine/api-reference/layout-related-objects)
  * [full text and formatting](/fine-reader/engine/api-reference/text-related-objects)
* [Compare documents](/fine-reader/engine/api-reference/document-comparison-objects)
* [Classify documents](/fine-reader/engine/api-reference/classification-related-objects)
* [Scan paper documents](/fine-reader/engine/api-reference/mechanism-objects) (Win) or [Export large documents in batches](/fine-reader/engine/api-reference/mechanism-objects) (Linux and macOS)

You may also find the additional information about ABBYY FineReader Engine functionality in:

* [Alphabetical List of the Objects and Interfaces](/fine-reader/engine/api-reference/alphabetical-list-of-objects-and-interfaces)
* [Object Diagram](/fine-reader/engine/api-reference/object-diagram)
* [Enumerations](/fine-reader/engine/api-reference/enumerations)
* [Return Codes](/fine-reader/engine/api-reference/return-codes)