Merging catalog labels means that two or more catalog labels are joined together into one single catalog label. You will normally need to merge catalog labels when you have existing labels with many images assigned which in the end turn out to cover the same meaning. In that case you will merge the two catalog labels together.
Relocating catalog labels is simple. Just select the catalog label that needs to be merged with another label. This is the label that you want to have removed after the merge. Then right click on the catalog label and select "Merge to another label..." from the context menu. That will open a separate catalog tree where you can select the label where the selected catalog label should be merge with. Remember; the original selected label will be merged with the selected label, so after the merge only the selected label will remain available.
When merging labels, all assigned images of the original label will also be brought over to the target label.
