mCommerce (or M-commerce) is using a mobile phone to make purchases. Like credit card transactions, your card/device can be either present or not present. In other words, “present” might mean your mobile is equipped with an application that you use to make a purchase in person, such as to buy a cup of coffee or a train ticket.
http://robertsiciliano.com/blog/2013/05/23/what-is-mcommerce-and-how-do-you-keep-transactions-safe-3/