The objects that form the backbone of your application and that are managed by the Spring IoC* container are called beans. A bean is an object that is instantiated, assembled, and otherwise managed by a Spring IoC container. These beans are created with the configuration metadata that you supply to the container, for example, in the form of XML definitions.
Spring beans are just object instances that are managed by the Spring container, namely, they are created and wired by the framework and put into a "bag of objects" (the container) from where you can get them later.
https://stackoverflow.com/questions/17193365/what-in-the-world-are-spring-beans