Multidimensional Expressions (MDX) is a query language used to retrieve and manipulate data from multidimensional databases, such as those used in Online Analytical Processing (OLAP). It allows users to perform complex calculations and queries on data organized in multiple dimensions, making it easier to analyze trends and patterns. MDX is particularly useful for business intelligence applications, as it enables users to create dynamic reports and dashboards. By leveraging its syntax, analysts can access specific data points, aggregate values, and filter results based on various criteria, enhancing decision-making processes in organizations.