A Marine Expeditionary Force (MEF) is a large, flexible, and rapidly deployable military unit in the United States Marine Corps. It typically consists of a ground combat element, an aviation combat element, and a logistics combat element, allowing it to conduct a wide range of operations. MEFs are designed to respond quickly to crises and can operate independently or as part of a larger joint force. Each MEF is commanded by a major general and can include thousands of Marines and sailors. They are often deployed for humanitarian assistance, disaster relief, or combat operations, showcasing the versatility and readiness of the U.S. Marine Corps.