title: what is the difference between <parent></parent>and<dependency><dependency> in maven?
body: <p>In my project I alway use <code>&lt;dependency&gt;&lt;dependency&gt;</code> but I can see <code>&lt;parent&gt;&lt;/parent&gt;</code> in some project <code>pom.xml</code> like:</p>
  
  <pre><code>&lt;parent&gt;
      &lt;groupId&gt;org.springframework.boot&lt;/groupId&gt;
      &lt;artifactId&gt;spring-boot-starter-parent&lt;/artifactId&gt;
      &lt;version&gt;1.5.2.RELEASE&lt;/version&gt;
  &lt;/parent&gt;
  </code></pre>
  
  <p>so I want to konw when to use it.</p>