Pulse oximetry is a non-invasive medical technique used to monitor the oxygen saturation of a patient's blood. It involves using a device called a pulse oximeter, which typically clips onto a patient's finger, toe, or earlobe. The pulse oximeter measures the proportion of oxygen-saturated hemoglobin in pulsating blood, giving healthcare providers valuable information about a patient's respiratory status and overall health. Pulse oximetry is commonly used in hospitals, clinics, and in-home care settings to monitor patients during surgery, in critical care units, and for patients with respiratory conditions.