UPS is a three-letter acronym for United Parcel Service, a global package delivery company. NEXTDAY is a seven-letter term referring to a type of delivery service offered by UPS that guarantees delivery of packages the next day. SPECIAL is also a seven-letter term referring to a type of delivery service offered by UPS that guarantees delivery of packages within a specified time frame. All three terms refer to different kinds of delivery services offered by UPS.