title: When should you "rebuild project" in intellij
body: <p><a href="https://www.jetbrains.com/help/idea/compilation-types.html?search=rebuild" rel="nofollow noreferrer">https://www.jetbrains.com/help/idea/compilation-types.html?search=rebuild</a></p>
  
  <p>According to that description of complication types, rebuilding a project recompiles all source files, and recommends its use when "classpath entries have changed, for example, SDKs or libraries being used added, removed or altered."</p>
  
  <p>I would appreciate some help interpreting this. I can imagine it may be necessary to recompile your class if a dependency changes or is removed, as it may no longer compile successfully. However, why would any <em>new</em> classes cause you to recompile existing ones?</p>