diff --git a/src/main/java/com/puppycrawl/tools/checkstyle/PropertyCacheFile.java b/src/main/java/com/puppycrawl/tools/checkstyle/PropertyCacheFile.java
index 79b1e372e..cdfa1a2d5 100644
--- a/src/main/java/com/puppycrawl/tools/checkstyle/PropertyCacheFile.java
+++ b/src/main/java/com/puppycrawl/tools/checkstyle/PropertyCacheFile.java
@@ -34,8 +34,11 @@ import com.puppycrawl.tools.checkstyle.api.Configuration;
 import com.puppycrawl.tools.checkstyle.api.Utils;
 
 /**
- * This class maintains a persistent store of the files that have
- * checked ok and their associated timestamp. It uses a property file
+ * This class maintains a persistent(on file-system) store of the files
+ * that have checked ok(no validation events) and their associated 
+ * timestamp. It is used to optimize Checkstyle between few launches.
+ * It is mostly useful for plugin and extensions of Checkstyle.  
+ * It uses a property file
  * for storage.  A hashcode of the Configuration is stored in the
  * cache file to ensure the cache is invalidated when the
  * configuration has changed.