Explain the difference between calculated columns and measures in Power BI. How can you create relationships between tables in Power BI? What are the different types of visualizations available in Power BI? What is DAX (Data Analysis Expressions), and why is it important in Power BI? How can you create a calculated measure using DAX in Power BI? What is Power Query, and how can it be used in Power BI? What is the difference between Power BI Desktop, Power BI Service, and Power BI Mobile? How can you share Power BI reports and dashboards with others? What is the role of Power Query in Power BI, and how can it be used to transform data? How can you handle complex data transformations using Power Query Editor? What are the different ways to create hierarchies in Power BI? How can you schedule data refresh in Power BI Service? What is the importance of Power BI Gateway, and when is it used? How can you create calculated tables in Power BI using DAX?