Cerebral oximetry is a medical diagnostic technology used to measure the oxygen levels in the brain. However, there are various other synonyms used for cerebral oximetry, such as near-infrared spectroscopy (NIRS), regional cerebral oxygen saturation (rScO2), and cerebral tissue oxygenation (CTO). These terms are often referred to interchangeably, as they all describe the same process, involving non-invasive monitoring of brain oxygenation. Regardless of what term is used, cerebral oximetry is crucial in many medical fields, including anesthesiology, neurology, and neonatology, to monitor brain function during surgeries, traumatic brain injuries, and other medical conditions. Understanding the different terms related to cerebral oximetry can be useful for medical professionals and patients alike.