diff --git a/interpreter/src/main/java/com/iluwatar/interpreter/App.java b/interpreter/src/main/java/com/iluwatar/interpreter/App.java
index 2273b386b..955563915 100644
--- a/interpreter/src/main/java/com/iluwatar/interpreter/App.java
+++ b/interpreter/src/main/java/com/iluwatar/interpreter/App.java
@@ -4,8 +4,14 @@ import java.util.Stack;
 
 /**
  * 
- * Interpreter pattern breaks sentences into expressions ({@link Expression}) that can
- * be evaluated and as a whole form the result.
+ * The Interpreter pattern is a design pattern that specifies how to evaluate sentences 
+ * in a language. The basic idea is to have a class for each symbol (terminal or nonterminal) 
+ * in a specialized computer language. The syntax tree of a sentence in the language is an 
+ * instance of the composite pattern and is used to evaluate (interpret) the sentence for a 
+ * client.
+ * <p>
+ * In this example we use the Interpreter pattern to break sentences into expressions 
+ * ({@link Expression}) that can be evaluated and as a whole form the result.
  * 
  */
 public class App {