IoT is like your nervous system, sensing the world by collecting and transmitting data via billions of connected devices around the world. AI is like your brain, analyzing all of that data and using it to think and make decisions, or perform actions that only humans could previously carry out. And blockchain is like your memory, creating a secure, indelible record of transactions and data exchanges.
In their E-book Oracle is explaining the development of three technologies that are changing business landscape (IoT, AI and blockchain). I especially like above written comparison for all three technologies. They do couple that explanation with their work in those technologies (this is for everybody to decide if they believe in their technology), but as starting point for general usage of those technologies, this e-book is a good description.