United MileagePlus is the loyalty program offered by United Airlines, which allows you to earn miles and redeem them for awards in travel, shopping, dining and more. Like many other miles programs, MileagePlus helps you make the most out of the miles you earn. You can qualify for different MileagePlus Premier status levels which gives you access to more exclusive rewards. Using certain credit cards that are tied to the program will qualify you as a member. Get more details through this link.