The Glasgow Coma Scale (GCS) is a scoring system used to assess the level of consciousness in patients with brain injury. It consists of three components: eye opening response, verbal response, and motor response. Each component is assigned a score, creating a total score ranging from 3 to 15. A higher score indicates a higher level of consciousness. The GCS is widely used in clinical practice and is easy to remember and interpret, making it a valuable tool for healthcare professionals in assessing and monitoring patients with brain injury.