Bookmark helps to identify a part of the document for future reference. The document elements like paragraph, table, etc., can be marked with a bookmark and it can be accessed by its name.
With DocIO, you can insert and delete bookmarks in the Word document.
Using bookmark navigator, you can navigate through the document elements and select a specific bookmark in the Word document.
Once after selecting a bookmark, you can edit, modify, or delete the contents within that bookmark.