What are the MTG Extort rules and how do they affect gameplay?

In Magic: The Gathering, Extort is an ability that allows a player to pay an additional cost when casting a spell to gain a benefit. When a player casts a spell with Extort, they can pay either a white or black mana to gain 1 life and deal 1 damage to each opponent. This ability can help players gain life and chip away at their opponents' life totals, providing a strategic advantage in gameplay.