This is how Maven sticks to its design philosophy, which is convention over configuration.

These two files are merged by Maven and form the Effective POM.

This pom file is known as effective pom file. A parent POM enables you to define an inheritance style relationship between POMs. commons-parent configures the source and target options in the maven-compiler-plugin to use the ${maven.compiler.source} and ${maven.compiler.target} properties respectively. Releasing A Parent POM. But if any dependency jar has been configured in parent and child POM both with different version then the child POM’s dependency version is … So all the dependencies which has been set in parent POM need not to set in child POM. Hence, we can create our own pom.xml file which will serve us as the parent project.Then, we can include there all configuration with dependencies and set this as the parent of … A child POM file inherits all the configuration elements from its parent POM file. 使用maven是为了更好的帮项目管理包依赖，maven的核心就是pom.xml。当我们需要引入一个jar包时，在pom文件中加上就可以从仓库中依赖到相应的jar包。现在有这样一个场景，有两个web项目A、B，一个java项目C，它们都需要用到同一个jar包：common.jar。 The pom file used by project is obtained by merging the project pom file, parent pom file (if any) and super pom file. Parent POM Maven also supports the notion of a parent POM. Maven supports inheritance in a way that each pom.xml file has the implicit parent POM, it's called Super POM and can be located in the Maven binaries. The following guide walks through most of the steps: Maven Project Common Release procedure; Note that Parent POMs have particular conventions for managing and deploying the project site. The parent POM can then be used to share certain properties and details of configuration. Releasing a Parent POM is much the same as any other Maven project. So, for example, to configure a component to have source/target set to 1.4 add the following lines to the component's pom…

Maven - Parent POM POM ( Project Object Model): A POM (Project Object Model) is the fundamental unit of work in Maven.It is an XML file that contains information about the project and configuration details used by Maven to build the project.It contains default values for most projects. b.创建子模account-register、account-persist:右击account-aggregator，new --> other --> Maven，选择Maven Module，创建moven模块。 c.创建完成后，项目结构如下，那么此时account-aggregator可以收缩起来了，我们操作具体子模块就好了。

POM files at the bottom of the hierarchy declare that they inherit from a specific parent POM. A POM can be a parent POM and it will be inherited to all child POM.