Spring Boot is a FRAMEWORK built on top of Spring framework. It eases out configuring & setting up of applications. This is not true not only for standalone applications but also for web-based applications. It reduces boilerplate CODE and minimizes the spring configuration a lot.

It scans the libraries on its classpath and AUTOMATICALLY configures the required classes. This gets us STARTED without writing much code.

Most of the times, Spring boot sets up the default configuration for libraries on its classpath. If your requirement is different from default configuration & setup, Spring boot provides an easy way of overriding the defaults. For example, let’s say you have a Spring Data library on the classpath. In this case, Spring Boot automatically sets up a connection to Database along with Data Source class. Let’s say if you want to change the port where the database is running, Spring Boot provides an easy way of configuring or overriding it. You can set up those in the application.properties ( or YAML /XML).

Spring Boot also provides opinionated Spring-based third-party libraries. They are known as Starters. The advantage is that a starter has all third party dependencies included hence this minimizes the configuration in the application. SECONDLY, starters also provide default setup & configuration which eases out the integration of the library into the application and get started.