How has the offside rule changed?

The original offside rule was that if any attacking player is ahead of the last defender when the ball is played then the attacking player must be given offside. The player must be given offside even if he doesn't receive the pass. The new rule is that the player can only be given offside if he is interfering with play i.e. he receives the ball, he obstructs defending players, blcoks the goalkeepers view, etc.