What are artificial neural networks (ANN)?

This article is part of Demystifying AI, a series of posts that (try to) disambiguate the jargon and myths surrounding AI. One of the most influential technologies of the past decade is artificial neural networks, the fundamental piece of deep learning algorithms, the bleeding edge of artificial intelligence. You can thank neural networks for many of applications you use every day, such as Google's translation service, Apple's Face ID iPhone lock and Amazon's Alexa AI-powered assistant. Neural networks are also behind some of the important artificial intelligence breakthroughs in other fields, such as diagnosing skin and breast cancer, and giving eyes to self-driving cars. The concept and science behind artificial neural networks have existed for many decades.