A Data Management Platform (DMP) is a resource that aggregates different kinds of data from online, offline and mobile sources. The data management platform also works on the data that is brought in, and typically allows users to access that data in various ways.
The idea behind a data management platform is that businesses must be able to take advantage of diverse kinds of information coming from a variety of sources, and collect that information in one central place in order to attain the business intelligence that truly benefits the enterprise.
Source: https://www.techopedia.com/definition/29397/data-management-platform-dmp