I relocated my images to a different folder and didn't use Lightroom to do it. I know, my bad. Of course, now the images in my collections cannot find the original image. Some of my collections have several hundred images.
What is the easiest way to have the previews in the collections locate the original images in their new location without doing them one by one.
If you just moved the folder to a new location, all you have to do is tell Lightroom where the new folder is, by using the Find Missing Folder command, and all the photos in this folder(s) will be reconnected, as explained at the two links provided above.
I suggest that you get out of the habit of moving photos or folders from here to there. Put them in their desired final location straight out of the camera, and then you will never run into these issues again.