Why do you override the equals() method?

Answer 1

Additional to Bhabeshs answer, if you override equals you have to override hashCode as well.
Because if a.equals(b), a.hashCode() must be the same as b.hashCode().

Answer 2

Because without overriding it works same as == operator which check for reference not for content equality.

Answer 3

@Tashi, Congratulations for Moderator badge. You really deserved it :-)

Answer 4

That's perfect Tashi. (y)