General Way: 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.
The “wiring” part there is what dependency injection is all about, what it means is that you can just say “I will need this thing” and the framework will follow some rules to get you the proper instance.
Technical Way: Central to the Spring Framework is its inversion of control container, which provides a consistent means of configuring and managing Java objects using reflection. The container is responsible for managing object lifecycles of specific objects: creating these objects, calling their initialization methods, and configuring these objects by wiring them together.
Objects created by the container are also called managed objects or beans. The container can be configured by loading XML files or detecting specific Java annotations on configuration classes. These data sources contain the bean definitions which provide the information required to create the beans.
Objects can be obtained by means of either dependency lookup or dependency injection. Dependency lookup is a pattern where a caller asks the container object for an object with a specific name or of a specific type. Dependency injection is a pattern where the container passes objects by name to other objects, via either constructors, properties, or factory methods.
You have to tailor the beans according to your need and inform Spring container to manage it when required, by using a methodology populalrly known as IoC (Inversion of Control) coined by Martin Fowler, also known as Dependency Injection (DI).
You wire the beans in a way, so that you do not have to take care of the instantiating or evaluate any dependency on the bean. This is popularly known as Hollywood Principle.
Just For Change 