APPLICATION.PROPERTIES: In Spring Boot, configuration details are kept in the application.properties file .The application.properties is present under the classpath(file location src/main/resources ).The basic configuration properties like DB details, server port etc. is present in the application.properties file as given below – spring.datasource.url=jdbc:oracle:thin:@manoj:1521:orcl spring.datasource.username=tog spring.datasource.password=sci YAML File: Spring Boot supports YAML based properties configurations to run the application. Instead of application.properties we can use application.yml file. This YAML file also should be kept inside the classpath( file location src/main/resources ). The sample application.yml file is given below datasource: driverClassName: oracle.jdbc.driver.OracleDriver url: jdbc:oracle:thin:@manoj:1521:orcl username: tog password: sci