title: What is Project Language level in IntelliJ IDEA?
body: <p>I am using Java 7 SDK and IntelliJ IDEA IDE.</p>
  
  <pre><code>java version "1.7.0_11"
  Java(TM) SE Runtime Environment (build 1.7.0_11-b21)
  Java HotSpot(TM) 64-Bit Server VM (build 23.6-b04, mixed mode)
  </code></pre>
  
  <p>I am still not able to use Java 7 features. After a bit of googling I could use all the features after setting project language level to <code>7(Diamond, ARM, multicatch etc)</code>. What exactly is this? If this has some relationship to syntax based on JDK in use what is <code>level 8(Lambda, annotations etc)</code>? Java 8 isn't released yet. Java 8 is expected in March 2014 according to Wiki. Someone please explain this language level concept.</p>