newbie need help with Ghost 15

Hi all..

I'm trying to find out how to do this correctly...My hard drive is on it's last legs, and I'm ready to swap it out with a new one..I now have the new hard drive, Ghost 15, and an external drive...

First, I need to know the difference between backing up the disk and copying the disk..Are they the same? If not, I'm assuming copying the old disk to the external disk, then switching out the old hard drive for the new one, and then somehow sending the copy back to the new hard drive is the procedure?

I've already backed up my 2 partitions , along with all files and folders to the external drive..

If I really needed to just copy the drives, does that mean I should erase the external drive and start over?

I need to be careful , as you can understand..This has to be done right and I've never worked with a backup program before..

Any help would be appreciated..