Enum feature added in Java 5 is a powerful and versatile feature of Java and yet underutilized. there are many advantages of using Enum like automatic serialization, Enum singleton are thread-safe and easiest way to write singleton apart from that Enum can be used as full blow Type like class in Java. some of those interesting usages of Enum are collected here.
Static keyword has a very an important role to play in a java program. If not used correctly it can hamper the output of the program. The static keyword is used with methods and variables as well. so here is a post that will help you understand the keyword STATIC.