What is a Spring bean?
Updated 2026-07-10 · Beginner friendly
Quick answer
A Spring bean is an object that the Spring container creates, configures, and manages for you. You mark a class as a bean with annotations like Component, Service, or Bean, and Spring keeps it in its application context ready to inject where needed. By default beans are singletons, meaning one shared instance per container.
How a bean is created
@Component
class EmailService { }
// or from a configuration method
@Bean
EmailService emailService() { return new EmailService(); }Common bean scopes
- Singleton: one shared instance per container, the default.
- Prototype: a new instance every time it is requested.
- Request and session: one per web request or user session.
In the interview
Be ready for the scope question. Say the default is singleton, one shared instance, and use prototype when you need a fresh object each time. Knowing that singleton is the default catches a common misconception.
Common follow up questions
Related interview questions
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