How to make a .iso file from your CD or DVD

To make an ISO from your CD/DVD, place the media in your drive but do
not mount it. 
 If it automounts, unmount it. 
 for DVD: 
 dd if=/dev/dvd of=dvd.iso  
 for CD: 
 dd if=/dev/cdrom of=cd.iso 
 SATA device 
 dd if=/dev/sr0 of=file.iso 
 SCSI device: 
 dd if=/dev/scd0 of=cd.iso