The Glasgow Coma Scale (GCS) is a neurological scale used to assess a patient's level of consciousness following a traumatic brain injury or other neurological events. It is composed of three components: eye opening response, verbal response, and motor response, with scores ranging from 3 (deep coma) to 15 (fully conscious). The GCS helps clinicians to quickly and objectively assess the severity of a patient's brain injury and monitor their progress over time. It is widely used in emergency departments, intensive care units, and other healthcare settings to guide treatment decisions and predict outcomes for patients with brain injury.