This video is a good description of machine learning.
https://youtu.be/WXHM_i-fgGo
There are a lot reasons why it gets so popular, but I guess one of the main reasons is the massive amount of research done by big companies. The industry is increasingly using it as a tool to predict all kinds of things they need to know in a lot of different areas. This is a very important part of the next industrial revolution.
The concept of machine learning isn't new, but the effectivity of it increased a lot because of new algorithms.
Here is an article about machine learning and the 4th industrial revolution:
https://medium.com/mmc-writes/the-fourth-industrial-revolution-a-primer-on-artificial-intelligence-ai-ff5e7fffcae1
