Artificial respiration refers to any measures used to cause air to flow in and out of the lungs when natural breathing is inadequate. There are manual methods like mouth-to-mouth and mechanical methods like ventilators. The key steps of CPR are to check for breathing, provide rescue breaths if needed, and perform chest compressions until emergency help arrives or the victim starts moving again. CPR involves restoring oxygenated blood flow to vital organs and should be commenced immediately for cardiac arrest victims to increase chances of survival.