//copy
Once you’ve made a selection, stand anywhere near or in your selection and type this command. Your location relative to your selection will matter later when you paste your selection elsewhere, so choose a spot that makes sense. For example, a lower corner is a good choice. A center point can also be useful.
//paste
Once you’ve copied your selection, travel to a new location where you would like to paste your selection. Where you stand when you type this command will determine the location of your pasted build. For example, if you were standing at the bottom left corner of your build when you copied your selection, your selection will paste into place with the bottom left corner at your new location.
After you’ve pasted your build, you can remove the original build by typing //set air.