Document widgets simply do a better job at displaying the documents that you store in your Document Central than  simply adding a "Document Link" to a text editor/Content Area. 

The "Free Viewers..." can be removed from the widget by updating the Widget settings if needed

Manually add any Document from Document central into this list widget by editing the widget

You can change the Title that fits in the colored banner above the document folders

There are 4 different Document widgets that you can use to organize your documents to your Site Visitors:

• Document Folder
• Document List
• Document Folder Box
• Document List Box