Flat File

What is a flat file?

Flat file is data file that contain records with no structured relationships

a textfile is the best example of flat file with no additional formatting or structure.

It is standard O/S File.

Flat File is nothing but a operating system file.
It is like a csv file ( comma separated value) or fixed length file.
For example, we have the data in one database. we want to upload into another database. So, this data from one database into flat file. and then, flat file imports into another database.

A flat-file is a flattened representation of some database stored in a single file.