The document summarizes the key differences between basic life support (BLS) and advanced cardiovascular life support (ACLS) for cardiac arrest and cardiopulmonary resuscitation. BLS focuses on oxygenation, ventilation, and circulation through chest compressions, breathing, and defibrillation if needed. ACLS adds advanced airway management, drug administration, and differential diagnosis. High-quality, minimally interrupted chest compressions are essential for both BLS and ACLS, and compressions should resume immediately after shock delivery during defibrillation.