Neural Networks are a class of Machine Learning models that were inspired by the human brain. They've exploded in popularity recently due to their effectiveness at attacking problems in a variety of subfields, like Computer Vision and Natural Language Processing.
If you're new to Neural Networks, I recommend reading my Neural Networks From Scratch Series first.
A simple walkthrough of deriving backpropagation for CNNs and implementing it from scratch in Python.Read
A simple guide to what CNNs are, how they work, and how to build one from scratch in Python.Read
A simple explanation of how they work and how to implement one from scratch in Python.Read