Transfer files, not copy them, to an external harddrive
I have a MacBook Pro running OS 10.13. It is getting full, so I'd like to 'transfer' files to an external hard drive. I googled and I see so much confusing information. Is there an easy way to achieve this?
Please note, I'd like to completely remove the files from my MacBook Pro.
MacBook Pro 13", macOS 10.13