Depends on how you do the transfer.
Connect the phone to the computer via USB cord and then if you just 'copy' them to an empty folder on the computer, a copy will be left on the phone.
If, however, you choose to 'move' them to the computer, then the only place they will be is on the computer. If you are trying to free up space on the phone, this is the better choice. You don't lose your images, just no longer have them on the phone.