The primary difference between chest compressions for an adult versus a small child lies in the compression depth, force, and hand placement. For adults, chest compressions require a depth of at least 2 to 2.4 inches (5-6 cm) using the heel of both hands on the center of the chest because adults have larger and more rigid chests. Small children require gentler compressions about 2 inches (5 cm) deep or roughly one-third the chest depth due to their smaller, more flexible bones, and often only one hand is used for compressions to avoid injury. Both adults and children should have compressions done at a rate of 100-120 per minute. Additionally, the compression-to-ventilation ratio for single rescuers is the same (30:2), but with two rescuers, children receive more frequent breaths (15:2) because their cardiac arrests are often due to respiratory issues. These modifications in technique ensure safe and effective CPR tailored to the anatomical and physiological differences between adults and children.