How does deep learning work?

The limitations discovered in machine learning caused scientists to look for other ways to build more complex models that allowed them to handle non-linear relationships and cases where there's a lot of interaction between the input of a model. This led to the invention of the artificial neural network. 

An artificial neural network is a graph composed of several layers of artificial neurons. It's inspired by how the structure and function of the biological brain found in humans and animals.

To understand the power of deep learning and how to use CNTK to build neural networks, we need to look at how a neural network works and how it is trained to detect patterns in samples you feed it.