Implied odd relate to making a call because of the likelyhood that you may make money later in the hand.

eg. People often call preflop raises with low pocket pairs. You may think 'they aren't getting pot odds to do this' and your right, they aren't. The reason they are calling is Implied odds. If they catch a set they have a strong hand which is hard to detect. If the player who raised preflop has a good hand, which is probable, then the player with the set stands to make a lot of money. Using implied odds takes this money into account.