A DSS uses software that allows managers to more fully utilize available information to assist in making decisions is the primary difference between a Marketing Information System (MIS) and a Decisions Support System (DSS).
A management information system that helps the marketers in making important decisions that are related to the marketing fields refers to the marketing information system. It is the system where the information that are associated with the marketing will be gathered and analysed for making important decisions by the marketing managers.
The information system that helps an organisation in making important decisions are called as Decision support system. The main thing that differentiates MIS and DSS is that A DSS uses software that allows managers to more fully utilize available information to assist in making decisions.