What are Spring Boot starter dependencies?

Spring Boot starters are dependency descriptors that bundle all necessary dependencies for a specific feature with compatible, tested versions. They follow the naming pattern: spring-boot-starter-{feature}. Common starters: spring-boot-starter-web — Spring MVC, embedded Tomcat, Jackson (JSON), validation; spring-boot-starter-data-jpa — Spring Data JPA, Hibernate, Spring ORM; spring-boot-starter-security — Spring Security; spring-boot-starter-test — JUnit 5, Mockito, AssertJ, Spring Test, MockMvc; spring-boot-starter-data-redis — Spring Data Redis, Lettuce client; spring-boot-starter-data-mongodb — Spring Data MongoDB; spring-boot-starter-cache — Spring caching support; spring-boot-starter-actuator — production monitoring; spring-boot-starter-validation — Bean Validation (Hibernate Validator); spring-boot-starter-mail — JavaMail, Spring Email; spring-boot-starter-amqp — Spring AMQP, RabbitMQ; spring-boot-starter-webflux — Spring WebFlux (reactive), Reactor Netty; spring-boot-starter-thymeleaf — Thymeleaf template engine. Parent POM: spring-boot-starter-parent manages versions for all starters — inherit it to get version management for free. spring-boot-dependencies BOM contains hundreds of dependency versions — used when you can't use the parent POM.