DFS is an algorithm used for relational and temporal datasets to automatically generate features by following relationships between data tables.

Calculating the MEAN of a customer’s transaction amounts is a depth 1 feature. Calculating the MAX of those MEAN values over several months is a "deep feature" with a depth of 2. 2. Deep Neural Networks

A "deep feature" has a depth greater than one, meaning it is created by stacking multiple mathematical operations (primitives).

In deep learning, "deep features" are the intermediate outputs from the hidden layers of a neural network. Deep Feature - an overview | ScienceDirect Topics