It stands for:
.D = Danger
.R = Response
.S = Shout for Help
.A = Airways
.B = Breathing
.C = Circulation
Firstly make sure that the ambulance is on it's way or to make call for emergency.
Then move on to the DR'S ABC uptill and untill ambulance or any professional medical help arrives.
DANGER
RESPONSE
Shake them gently by shoulders and ask them "Are u alright...??? ". If there is no response then move on to the next step.
SHOUT FOR HELP
AIRWAYS
Gently turn the head back in the direction shown here to open up the airways.
BREATHING
Look , Listen and Feel for sense of normal breathing. Look for normal chest movements. Try to feel their breath against your face.
Do this for not more than 10seconds if there is no sign for breathing or their breathing is an unusual or in noisy way then we need to move to the next step.
CIRCULATION
Still if there is an unusal situation ; the breathing is not overcome so we need to improve the circulation which means to improve the flow of blood around the body when the heart stops pumping and we need to start CPR to improve the circulation.