Word generates code that is hidden in your Word document to enable it to communicate with EndNote. When you click on an in-text citation or on your bibliography, the background will go grey indicating that code is present.
Now you can:
If you wish to edit a reference that you have inserted into a Word document, make the changes to the reference in your EndNote Library.
Then, return to Word and click on Update Citations and Bibliography in the EndNote toolbar. The reference will be updated in Word.
As you begin to insert citations, EndNote Desktop automatically creates a new group containing those references. This group has the same name as your Word document. This is a useful way to see which of the references in your Library you have used in your work. When you close Word or EndNote and re-open them, the group is not automatically displayed in EndNote. Open your Word document and from the EndNote toolbar select Update Citations and Bibliography to see the group re-appear in EndNote.