I'm relatively new to Lightroom so not on top of it yet. Here's what I want to achieve: My Air has 256 GB of storage, so I need to regularly move my photos to a hard drive. So far I've just exported the photos into folders and subsequently deleted them from the disk on my Air. However, I'd like to retain the organisational and editing capacities of Lightroom without having to reimport the images into Lightroom, and also be able to save them in their original RAW-format. However, I don't want to move my entire Lightroom library to my external drive, because I frequently edit and post on the go. So, basically, old photos that I no longer work with but want to keep go to the external drive, and my 'current' plus a few old ones I want to have easy access to stay on my Air. I'm a bit confused about the relationship between libraries and catalogues. Are catalogues the way forward for me, setting up catalogues and then moving the catalogue file to the external drive? Or is it possible to just set up different Lightroom libraries? What is the best way forward? Thanks.