title: Maven compiler plugin jdk versions for source and target
body: <p>I have the following configuration in my pom.xml for maven-compiler-plugin.</p>
  
  <pre><code>&lt;plugin&gt;
      &lt;groupId&gt;org.apache.maven.plugins&lt;/groupId&gt;
      &lt;artifactId&gt;maven-compiler-plugin&lt;/artifactId&gt;
      &lt;version&gt;2.3.2&lt;/version&gt;
      &lt;configuration&gt;
          &lt;source&gt;1.8&lt;/source&gt;
          &lt;target&gt;1.8&lt;/target&gt;
      &lt;/configuration&gt;
  &lt;/plugin&gt;
  </code></pre>
  
  <p>What should be the source and target version of jdk? How it depends on version of jdk installed on my computer? May they be different? e.g. installed jdk is 1.8, in source parameter - 1.6, target - 1.7.</p>