Power BI stores its data in two primary repositories, that is Azure BLOB storage, and Azure SQL Database. All the data that is uploaded by users are sent straight to Azure BLOB Storage, and the rest of the data like Metadata, as well as other related information for the system, are stored in Azure SQL Database.
Wishing to learn Power BI and get certified? Check out the Power BI certification course from Intellipaat which is co-developed by Microsoft. This course is of 24hrs that also comes with dedicated 30hrs for project-work and exercises to help you gain the required practical skills. Also, check out our video on Power BI Tutorial For Beginners.