Spring vs Spring Boot

In this post, we will learn the difference between Spring and Spring Boot in Java. This is a frequently asked question in Java interviews for beginners. Let's dive into it. 

What is Spring? 

Spring is a powerful, lightweight framework used for developing Java applications. It offers comprehensive infrastructure support for developing robust Java applications, reducing the need for developers to focus on tedious processes such as manual garbage collection and memory management.

Spring provides a wide array of features including Inversion of Control (IoC), Aspect-Oriented Programming (AOP), data access, transaction management, and more. However, these features also bring complexity, as developers need to spend significant time handling the configuration details of the Spring Framework. 

What is Spring Boot? 

Spring Boot, on the other hand, is built on top of the Spring framework. It was introduced to simplify the bootstrapping and development of Spring applications. It achieves this by providing defaults for code and annotation configuration, thereby reducing the need for boilerplate code. 

Spring Boot makes it easier to create stand-alone, production-grade Spring-based applications by providing functionalities like auto-configuration, an embedded server, and dependency management.

Difference between Spring and Spring Boot in Java

Spring Spring Boot
Spring Framework is an open-source Java platform that provides comprehensive infrastructure support for developing Java applications. Spring Boot is built on top of Spring. It simplifies Spring application bootstrapping by providing automatic configuration and runtime simplicity.
Spring requires a lot of manual configuration. You have to set up everything yourself. Spring Boot offers auto-configuration for an application, reducing the need for manual setup and configuration.
To set up a Spring application, developers need to spend a lot of time in XML or annotation-based configuration. Spring Boot reduces development time by automatically managing the configuration based on the included dependencies.
In Spring, the management of dependencies can be a bit complex. Spring Boot uses a starter POMs approach, where each POM represents a set of dependencies, simplifying dependency management.
Spring doesn't provide any embedded server, so you must deploy the built war/ear file to a separate server. Spring Boot provides an embedded server like Tomcat, Jetty, or Undertow, so there is no need to deploy the war file. The application can be run as a standalone application.
Testing a Spring application may require writing more boilerplate code. Spring Boot makes writing tests easier with the help of features like @SpringBootTest.
In Spring, developers have to manually define the main class for application startup. Spring Boot implicitly defines the main class for application startup.
Spring doesn’t provide any specific way to create production-ready applications. Spring Boot provides features like health checks, metrics, etc. to create production-ready applications.