The drill down term is basically used in the information technology for the explore the multidimensional information or data by navigating the different layers of the data from the web page applications.
Drill down basically involve in the database by accessing the specific information through the database queries. Each query basically increase the data granularity. This term is also involve with the link for represent the details more specifically.
The drill down is the simple approach or technique for dividing the complex problems into small parts so that it make the technique more efficient.