title: What does "mvn -P" do?
body: <p>I have been told to use <code>mvn clean install -P base</code> at work for a particular task. I am trying to find what it exactly means.</p>
  
  <p>According to <a href="https://maven.apache.org/archives/maven-1.x/reference/command-line.html" rel="noreferrer">https://maven.apache.org/archives/maven-1.x/reference/command-line.html</a> , <code>-P</code> lists all available plugins; and <code>-p</code> is used to specify a project file (assuming pom).</p>
  
  <p>But when I typed <code>mvn -P</code> in my command line, I got an error saying: </p>
  
  <p>Unable to parse command line options: Missing argument for option: P</p>
  
  <pre><code>usage: mvn [options] [&lt;goal(s)&gt;] [&lt;phase(s)&gt;]
  </code></pre>
  
  <p>What do the <code>-P</code> and <code>-p</code> stand for, and what are they used for exactly?</p>