Hi SMK, Photos don't reside IN the Lightroom catalog. The catalog only contains information about your photos. It references your photos wherever you have chosen to store them on your hard drive. People get confused because LR actually does store three "previews" of your photos - JPEG copies - a small thumbnail, a screensize one, and a full size one - this is why you can "see" your photos in LR even when LR says that it can't find your files. To your question about how to move folders in a way that they don't go missing, it's easy once you know how: do this from within Lightroom using the Folders panel - in a nutshell, click and drag. Since you're doing these operations from within Lightroom, it doesn't lose track of your images. (If you do this outside of LR, LR can't see you do it, so it does lose track.) I move photos and folders all the time using Lightroom's Folders panel, and I teach this as well. This video tutorial will give you all the file management skills you'll likely need for photos that you have imported, and I promise it will be worth 20 minutes of your time - it's one of the most important lessons I teach. You say that for a particular project you have a catalog with a few folders. For most people I recommend that they have just one catalog, and that they import ALL of their photos into it. Then if you want to pull together a specific subset of them for a project, use collections. Here's a page on my Lightroom blog that has several articles and video tutorials for Lightroom beginners - do check it out. I hope this helps - feel free to respond with questions.
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