Spring Boot has been built on top of Spring framework. By using it we can skip writing the boilerplate code like configuring the Database or Messaging Queues, XML CONFIGURATIONS, setting build path and maven dependencies. Spring Boot can be assumed as the upgradation of existing Spring functionalities to make it robust and easy to USE; that is required for building modern cloud applications.

Spring Boot PROVIDES an opinionated view by making certain elementary decisions while developing and running the application. Spring Boot uses sensible defaults, mostly based on the classpath contents. For example, Spring Boot sets up JPA Entity Manager Factory if JPA dependencies are in the classpath. However, it provides us the ability to override the defaults as and when required.

Another important aspect of Spring Boot is embedded servers. Traditionally, with Java web applications we build a WAR or EAR file and deploy them into servers like Tomcat or JBoss etc. Hence, we need to pre-install a web/application server before deploying the WAR/EAR files. Whereas in Spring Boot the web server (Tomcat or Jetty) is part of the application JAR. To deploy applications using embedded servers, it is sufficient if; Java is INSTALLED on the server.

Spring Boot is considered as the future of Spring, with most of the cloud-based Microservices being built on it. Most of the upcoming Spring projects are COMPLETELY integrated with Boot like example Spring Cloud Contracts, Spring Boot Admin, etc. required for cloud application development.