Which system transports oxygen, nutrients, and wastes, fights infection, regulate body temperature?

The analogy says that stem cells were important for medicine, just as the internet was important for communication, because if you look, thanks to the internet, different social networks and different media have emerged. Nowadays it helps a lot of people in different cases, like online classes for certain schools. Without the internet, people would still be talking in person, and in these quarantine times it would not be possible. And the internet also made it possible for strangers to connect, making multiple communities.

I hope I helped, even speaking only on the technology side.