Spring Boot is an open-source Java framework used for programming standalone, production-grade Spring-based applications with minimal effort.
Spring Boot is a convention-over-configuration extension for the Spring Java platform intended to help minimize configuration concerns while creating Spring-based applications.
Most of the application can be preconfigured using Spring team's "opinionated view" of the best configuration and use of the Spring platform and third-party libraries.
It is widely used for building microservices, web applications, and other Java-based projects due to its ease of use and robustness.