A window opening over the page. The dangerous kind imitates a system warning — but a genuine virus alert never arrives from a website you happen to be visiting.
The drawing that proves the sentence above. It is the same card that is in the book.
Think of it as
a salesman stepping in front of the shelf.
For example
A window appears saying your computer is infected and to call a number. A real warning never arrives from a page you are visiting.
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.