An EJB Container is a runtime environment that manages the execution of Enterprise JavaBeans (EJB), which are server-side components used in Java applications. The container provides essential services such as transaction management, security, and concurrency control, allowing developers to focus on business logic rather than infrastructure concerns. The EJB Container also handles the lifecycle of EJBs, including their creation, activation, and destruction. It ensures that beans are properly pooled and reused, optimizing resource usage. By providing these services, the EJB Container simplifies the development of scalable and robust enterprise applications in the Java EE ecosystem.