An Engineer's trek into Machine Learning

You are a Software Engineer. You notice Artificial Intelligence, Machine Learning, Deep Learning, Data Science buzzwords all around. You wonder what these phrases mean, whether all this is for real and useful or is yet another hype and passing fad. You want to figure out how it is changing or will change the computer/IT industry, and why you should care, if at all. You google about it, you read various articles, blogs, and tutorials.