# Document Object Model

> The document model behind the WPF TextControl: text parts, IFormattedText, frames and sections, why collections follow the input focus, and the 1/96 inch unit.

- **Product:** TX Text Control .NET for WPF
- **Section:** Documentation
- **Kind:** Topic
- **Path:** TX Text Control .NET for WPF > Document Processing > Document Object Model
- **Web URL:** https://docs.textcontrol.com/tx-text-control-dotnet-wpf/document-processing/object-model/
- **LLMs URL:** https://docs.textcontrol.com/tx-text-control-dotnet-wpf/document-processing/object-model/llms.txt
- **LLMs-Full URL:** https://docs.textcontrol.com/tx-text-control-dotnet-wpf/document-processing/object-model/llms-full.txt

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## On This Page

- [Two Classes, One Document Model](https://docs.textcontrol.com/tx-text-control-dotnet-wpf/document-processing/object-model/#two-classes-one-document-model)
- [What a Document Consists of](https://docs.textcontrol.com/tx-text-control-dotnet-wpf/document-processing/object-model/#what-a-document-consists-of)
- [The Class Hierarchy](https://docs.textcontrol.com/tx-text-control-dotnet-wpf/document-processing/object-model/#the-class-hierarchy)
- [The Input Focus Decides What a Collection Contains](https://docs.textcontrol.com/tx-text-control-dotnet-wpf/document-processing/object-model/#the-input-focus-decides-what-a-collection-contains)
- [Positions and Units](https://docs.textcontrol.com/tx-text-control-dotnet-wpf/document-processing/object-model/#positions-and-units)
- [Example](https://docs.textcontrol.com/tx-text-control-dotnet-wpf/document-processing/object-model/#example)
- [Where Each Element Is Described](https://docs.textcontrol.com/tx-text-control-dotnet-wpf/document-processing/object-model/#where-each-element-is-described)
- [Key Members](https://docs.textcontrol.com/tx-text-control-dotnet-wpf/document-processing/object-model/#key-members)
- [Next Steps](https://docs.textcontrol.com/tx-text-control-dotnet-wpf/document-processing/object-model/#next-steps)

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## Nearby

- **Previous:** [Document Processing](https://docs.textcontrol.com/tx-text-control-dotnet-wpf/document-processing/llms.txt)
- **Next:** [Creating Documents](https://docs.textcontrol.com/tx-text-control-dotnet-wpf/document-processing/creating/llms.txt)