Spring Boot is an open-source, Java-based framework designed to simplify the development of production-ready Spring applications. It is built on top of the Spring Framework and provides a streamlined way to create standalone, production-grade applications with minimal configuration.

Key Features of Spring Boot

1. Auto-Configuration: Spring Boot automatically configures your application based on the dependencies you include in your project. For example, if you add spring-boot-starter-web, it configures a web server like Tomcat automatically.

2. Starter Dependencies: Spring Boot provides starter dependencies (e.g., spring-boot-starter-web, spring-boot-starter-data-jpa) to simplify dependency management. These starters bundle commonly used libraries for specific functionalities.

3. Embedded Servers: It includes embedded servers like Tomcat, Jetty, or Undertow, allowing you to run applications without deploying them to an external server.

4. Annotation-Based Configuration: Spring Boot reduces the need for XML configuration by using annotations like @SpringBootApplication, @RestController, and @Component.

5. Spring Initializr: A web-based tool to generate Spring Boot projects with pre-configured dependencies.

6. Actuator: Provides production-ready features like monitoring, metrics, and health checks.

7. Microservices Support: Spring Boot is widely used for building microservices due to its lightweight and modular nature.