Before delving into the technical aspects of data warehousing, it is essential to have a thorough understanding of the basic concepts and principles. Data warehousing involves collecting, integrating, transforming, and storing data from multiple sources in a centralized and consistent format. This process primarily supports decision making, reporting, and analytics. Key terms and concepts to be aware of include data warehouse, data mart, ETL (Extract, Transform, Load), OLAP (Online Analytical Processing), and data modeling. A data warehouse is a database that contains structured and historical data from various sources that are organized by subject areas and dimensions. Data mart is a subset of a data warehouse that focuses on a particular business function or domain such as sales, marketing, or finance. ETL is a process that extracts data from source systems, transforms it into a suitable format, and loads it into either a data warehouse or a data mart. OLAP is an approach that enables users to perform multidimensional analysis and queries on the data stored in either a data warehouse or a data mart. Data modeling is the practice of designing and defining the structure, relationships, and constraints of data in either a data warehouse or a data mart.