In the Spring Framework, a bean is simply a Java object that is instantiated, configured, and entirely managed by the Spring Inversion of Control (IoC) container.
Instead of you manually creating an object using the new keyword, the Spring container takes over this responsibility, handling the object’s entire lifecycle from creation to destruction. Beans form the foundational backbone of any Spring or Spring Boot application.
On another note:
A bean is an object that is instantiated, assembled, and managed by a Spring IoC container. Otherwise, a bean is simply one of many objects in your application. Beans, and the dependencies among them, are reflected in the configuration metadata used by a container. The IoC Container Container Overview. Spring Framework.