We all get to the stage where images are stored on different drives and sometimes we won't have access to those drives.

Especially when working on a laptop, a desk drive might be in a different location and the images on it temporarily inaccessible.

Lightroom has a handy feature for this very situation, called Smart Previews.

Smart Previews allow you to edit images when Lightroom can't access the original file, it contains all of your edits to the file made when the image was accessible.