The following article explains When to Use Beans in Spring.

In Spring, a bean is a Java object that the Spring IoC container creates and manages. In fact, these are the building blocks of a Spring application, and they can represent any object that the Java Virtual Machine (JVM) can instantiate. The following list shows some scenarios where you might want to use beans in Spring.

  1. Dependency Injection. As a matter of fact, Spring’s Dependency Injection (DI) mechanism relies heavily on beans. So, in DI, they are used to define the dependencies of other beans, which are then injected at runtime by the Spring container.
  2. Aspect-Oriented Programming. Likewise, Spring’s Aspect-Oriented Programming (AOP) framework uses beans to define aspects and advice.
  3. Data Access. Also, Spring provides a rich set of data access APIs, and many of them rely on beans to define data sources, transaction managers, and other components.
  4. Web Development. Similarly, Spring’s web framework, Spring MVC, uses them extensively to define controllers, view resolvers, and other web-related components.
  5. Integration. Furthermore, Spring Integration is a framework for integrating disparate systems, and it relies heavily on them to define channels, message handlers, and other integration components.

In general, if you’re developing a Spring application, you’ll likely be using beans to define the various components of your application. Since they allow you to modularize your application and easily manage the dependencies between different components.

Further Reading

Spring Framework Practice Problems and Their Solutions

Java Practice Exercise