@rashida Usually a defibrillator is used in conjunction with CPR.
BUT...Let's put it another way- if you need CPR or definrillation, your heart has ceased to function well enough to sustain life. What a DNR order means is that at that point all efforts to revive you stop and you die.

IF YOU ARE DNR, that info needs to be on your person ALL the time. If it is not, and nobody is with you to hand it over, in writing, emergency responders WILL try to revive you. By that I mean police, fire, EMTs, paramedics, and even bystanders who know CPR or have access to a defibrillator.
So if you truly do not want resuscitation, wear a medical alert type necklace and bracelet that state DNR and direct responders where to find the document - like wallet, purse, refrigerator door. Meke sure your loved ones know it too, and keep a copy with your insurance card in case of hospitalization.