Copying files is an everyday task. You’ll copy files from one folder to another so you can have multiple versions; you’ll copy files onto removable disks to give to someone else or as backup for yourself; you’ll copy files from removable disks onto your Mac’s hard disk so you can use them; and you’ll probably find a number of other reasons to copy files. When you duplicate or copy folders, every item contained within that folder is also copied.
Go back to work while the computer is copying
If you have a large file to copy, you can go back to work on something else while the computer is going through its copying process. You can go back to your application, browse through your windows, empty the Trash, connect to the Internet, ...