Computer Science An Overview _J. Glenn Brookshear _11th Edition

The term database refers to a collection of data that is multidimensional in the
sense that internal links between its entries make the information accessible
from a variety of perspectives. This is in contrast to a traditional file system
(Section 9.5), sometimes called a flat file, which is a one-dimensional storage
system, meaning that it presents its information from a single point of view.

flat file