66. What is Power BI?
Answer:
Power BI is a Business Intelligence (BI) tool developed by Microsoft that helps users connect, transform, analyze, and visualize data through interactive dashboards and reports.
Key Features:
โ Data Visualization
โ Dashboard Creation
โ Data Modeling
โ DAX Calculations
โ Data Sharing
67. Difference Between Power BI Desktop and Power BI Service
Feature | Power BI Desktop | Power BI Service
Purpose | Used to build reports | Used to share reports
Platform | Installed locally | Cloud-based
Main Use | Data modeling | Collaboration
Cost | Free | Requires licensing for advanced features
68. What is DAX?
Answer:
DAX (Data Analysis Expressions) is the formula language used in Power BI.
Used for:
โ Measures
โ Calculated Columns
โ Calculated Tables
Example:
Total Sales = SUM(Sales[SalesAmount])
69. What is Power Query?
Answer:
Power Query is Power BI's ETL tool.
ETL : Extract, Transform, Load
Used for:
โ Data Cleaning
โ Data Transformation
โ Data Integration
โ Data Preparation
Common Tasks:
Remove duplicates, Split columns, Merge tables, Replace values
70. What are Calculated Columns?
Answer:
Calculated Columns create new columns using DAX.
Example:
Profit = Sales[Revenue] - Sales[Cost]Stored in the data model.
71. Difference Between Measures and Calculated Columns
Feature | Measure | Calculated Column
Calculation | Calculated on demand | Stored in model
Behavior | Dynamic | Static
Memory | Uses less memory | Uses more memory
Usage | Used in visuals | Used in rows
Example Measure:
Total Sales = SUM(Sales[Amount])