AbstractNowadays, companies and organizations manage large amounts of data to be used as support in decision making. A good solution for data management is in the form of data warehouses. A data warehouse is used to gather information from multiple sources within a company and arrange the information in a way that makes it easy to retrieve and analyze. Designing a data warehouse is not a simple task. The study herein will focus on what a data warehouse is and how the ETL process is used for data storage in the data warehouse. ETL stands for Extract, Transform and Load and is the process that retrieves data, transforms it and finally loads it into the data warehouse.