Tools
Image
Document
Object
Miscellaneous

Preferences: Image
Imported Images are:

Copied: Image files that are dragged into a Create document are stored within the document. This increases the size of the Create document and ensures that all images are available to the document.

Linked: The

Create document will store only the path of dragged in image files. If you move the image file, the next time you open the Create document, Create will display a dialog box asking you to relocate the document.