valueOf function of enum

[Time]

enum birds
{
 parrot,cock,hen,sparrow
}
class demo
{
 public static void main(String b[])
 {
    System.out.println(birds.valueOf("parrot")); 
    System.out.println(birds.parrot);
 }
}

Output is:
parrot
parrot.. i cant find any use of valueOf function of enum..Does someone know any practical use of this method?