What is a Raw Reflection FootPrint

HI Guys,
I am very new to Dremio and was wondering what exactly is a footprint as i am under the impression that Dremio does not create a copy of the data. so I am just wondering what is the meaning of the raw reflection footprint.

I have a few reflections that has a footprint of 49 GB


Reflections are columnar format PARQUET copy of the base data based on the dataset the REFLECTION is built. For example if you have a EMPLOYEES table in Postgres and you create a view on Dremio for all employees in a certain department and you create a reflection on the view. The employee data for that department will be created in the distributed storage you have specified in PARQUET format



Thank you very much this actually helped.
Really appreciate the simplistic explanation