With regard to data migration, what is referred to as a Three-Tier System?

This is another question that will test your knowledge of data migration and data warehousing. You can assume the interviewer will have access to a wide range of technical and operational questions they can ask you. While there is no way you can study and be prepared for every single question, you should be able to handle most of them. If you're asked a question you can't answer, simply tell the interviewer that you don't have that information handy, and then describe how you would go about locating it.

"The data warehouse is the 3-tier system in data migration. The first tier is the end-users or the front end. The middle tier in data migration provides end-users the data that they can use and which is secure. The final tier is the back end, where the data is stored."