Everyday objects given a chip and a connection. The cheap ones often never receive a security update, which is what makes them the weakest thing on your network.
The drawing that proves the sentence above. It is the same card that is in the book.
Think of it as
furniture that can send postcards.
For example
The cheap plug you bought in 2021 still works. It has also never once had a security update, and it is on the same network as your laptop.
This is one card out of 275.
The hundred words you meet most are free — the whole set, animated, in one file that works with no internet.
Volume 1 has all 275 in fifteen chapters, with Staying Safe the largest chapter on purpose.