IoT, or Internet of Things, is a networking concept where two or more (often a LOT more) devices all communicate with each other. A WiFi module may or may not be included in the mix, depending on how those individual devices connect to the Internet. In any case, some sort of embedded system is required in each device to moderate, monitor, send and receive network communications traffic. So, yeah, an embedded system is used with each IoT device. And if the device uses a WiFi connection to the Internet, the embedded system controls that too, along with everything else the device does. You can call it automation if you want to, but IoT is sooo much more than just simple automation, which doesn't require ANY Internet connection to do its thing.
Making "smart" devices that you can communicate with from anywhere in the world is a global game changer. Hackers love this, infecting Internet-connected computers with malware to create bot-nets for all sorts of nefarious purposes. It's a growing business, designing IoT devices with secure interfaces to the Internet. Gotta stay at least two steps ahead of the hackers and be on the look-out for vulnerabilities in the hardware and the programs that drive it. Get very good at it (hacking or defending) and you can earn big bux.