Since the data warehouse is a project, you need a flexible approach to implement it as effectively as possible. A data warehouse stores current and past data in one place and, at the same time, acts as a single source of information for a company. The data in a data warehouse comes from the organization's operating systems, as well as from other external sources. The data storage area does not provide, as soon as possible, a system that provides query or presentation services, but is classified as a presentation server.
A data model provides a framework of relationships between the data elements in a database, as well as a guide for using the data.
