Lightroom 6 will see your catalog and will prompt you to allow it to be upgraded. This will result in the creation of a new catalog using the database format needed by Lightroom 6. Your existing Lightroom 5 catalog will remain intact and usable by Lightroom 5 if you decide to keep both versions on your computer. Take note that the Lightroom 6 catalog will never be opened by Lightroom 5. The conversion is forward compatible, but not backward compatible.
Thanks. Is there a way I can check to determine if the upgrade was made? Sorry, I don't remember being asked to upgrade the LR 5 catalog. If it has been accomplished, is there any need to keep the LR5 catalog? It give me the creeps to delete anything associated with the catalog. I've deleted the LR 5 software so I won't be using it again.
If you are using Lightroom 6, and all of your work is there as you expect it to be, then the conversion took place. That's all there is to it. You might want to keep the Lightroom 5 catalog just in case something goes wrong before you make a scheduled backup of the Lightroom 6 catalog. But, technically speaking, you don't need the old catalog. Lightroom 6 isn't going to use it. If you try to open it, Lightroom will convert it again, and you will be back at the point you were in that catalog.
Thanks, Jim. Sorry to beg the issue, but one can never be too careful.