Linearize PDF Node
The Linearize node converts the document to a web optimized format sometimes also called "Fast Web View".
General Settings
Linearization (Fast Web View) restructures the documents internal structure and content so that the pages load in order. When linearizing the content is just reorganized internally. No content is altered or removed so the PDF will be displayed exactly the same as it was prior to conversion.
This allows large documents to load faster when downloading from a web. Having the document structure and content in a linearized (from beginning to end) order allows a browser to immediately display the first page as the remainder of the document is still being loaded.
Note: In order to see the complete speed benefits the server where the PDF is being hosted must also support page by page loading.