# Adobe PDF Library 21 Adobe C++ API Reference APDFL21.0.0PlusP1f

> The Adobe PDF Library Adobe C++ API provides low-level access to PDF document manipulation. The API is organized into functional layers, each containing related functions, definitions, and data types.

- Product: Adobe PDF Library 21
- Language: Adobe C++
- Version: APDFL21.0.0PlusP1f
- HTML page: https://docs.datalogics.com/apdfl21/AdobeCPlusCPlus/APDFL21.0.0PlusP1f
- Version index: https://docs.datalogics.com/apdfl21/AdobeCPlusCPlus/APDFL21.0.0PlusP1f/llms.txt

The Adobe PDF Library Adobe C++ API provides low-level access to PDF document manipulation. The API is organized into functional layers, each containing related functions, definitions, and data types.

## Layers

- [Acro Support Layer](https://docs.datalogics.com/apdfl21/AdobeCPlusCPlus/APDFL21.0.0PlusP1f/aslayer.md): 21 components, 742 items.
- [COS Layer](https://docs.datalogics.com/apdfl21/AdobeCPlusCPlus/APDFL21.0.0PlusP1f/coslayer.md): 12 components, 139 items.
- [PD Layer](https://docs.datalogics.com/apdfl21/AdobeCPlusCPlus/APDFL21.0.0PlusP1f/pdlayer.md): 47 components, 1136 items.
- [PDF Edit Layer](https://docs.datalogics.com/apdfl21/AdobeCPlusCPlus/APDFL21.0.0PlusP1f/pdelayer.md): 37 components, 479 items.
- [PDSEdit Layer](https://docs.datalogics.com/apdfl21/AdobeCPlusCPlus/APDFL21.0.0PlusP1f/pdslayer.md): 7 components, 135 items.
- [PDFL Library Layer](https://docs.datalogics.com/apdfl21/AdobeCPlusCPlus/APDFL21.0.0PlusP1f/pdfllayer.md): 11 components, 187 items.
- [Acro Color Layer](https://docs.datalogics.com/apdfl21/AdobeCPlusCPlus/APDFL21.0.0PlusP1f/acrocolor.md): 1 components, 115 items.
- [APDFL Plugins](https://docs.datalogics.com/apdfl21/AdobeCPlusCPlus/APDFL21.0.0PlusP1f/plugins.md): 6 components, 116 items.
- [Forms Extension](https://docs.datalogics.com/apdfl21/AdobeCPlusCPlus/APDFL21.0.0PlusP1f/formsextension.md): 2 components, 20 items.
- [Additional functionality from Datalogics](https://docs.datalogics.com/apdfl21/AdobeCPlusCPlus/APDFL21.0.0PlusP1f/dlextras.md): 22 components, 215 items.