How do ETL tools work?

Related questions

1. What is datawarehouse testing?
2. What does an ETL job do?
3. Why ETL Testing is required?
4. What is an ETL label?
5. Is Hadoop a ETL tool?
6. What are ETL jobs?
7. Is ETL Testing difficult?
8. What is ETL Testing?
9. What is ETL in SQL?
10. What is ETL tools for Oracle?

Tags

1. #tools
2. #example
3. #warehouse
4. #database
5. #perform
6. #transformation
7. #several
8. #heterogeneous
9. #operations
10. #loading
11. #system
12. #extract
13. #extraction
14. #further
15. #source
16. #programmatic
17. #transform
18. #another
19. #which
20. #meant