It allows streamline the checkout process by splitting it into multiple steps. How you can benefit from it: You can set the checkout type that your users prefer: many A/B split tests have proved that online buyers prefer a neat view without too many fields on the same page when ending the checkout process; You can substantially reduce the percentage of abandoned carts caused by a too long checkout page and with too many fields to fill in; You can reduce the number of steps and the cognitive effort required to the user by combining some steps of the checkout process into one (Billing & Shipping, Order info & Payment).