title: Maven terms -- dependency and plugin, repository vs. pluginRepository
body: <p>I've been working with Maven for days but still get confused about some of the terms:</p>
  
  <p>First question is what is the difference between <code>repository</code> and <code>pluginRepository</code>? If there is functional difference so shall I put one url for both?</p>
  
  <p>Second question is what is the difference between <code>dependency</code> and <code>plugin</code>? Maybe they are totally different item to compare because <code>plugin</code> can include <code>dependencies</code>, but to me <code>plugins</code> look like some kind of dependencies in a build? Just like "This <code>build</code> depends on these plugins, and one of this plugin depends on that dependencies", I always think dependencies are kind of library jars, and plugins are library jars or depending projects in jars...</p>
  
  <p>Sorry if the question is kind of dumb, but I am really confused. Please give a hint, thanks.</p>