A small add-on that can usually read every page you visit. Useful ones exist, but extensions get sold to new owners and the permissions quietly carry over.
The drawing that proves the sentence above. It is the same card that is in the book.
Think of it as
a tool clipped onto the penknife.
For example
You added a little tool for coupons. It can read every page you open, including your bank, because that is what you agreed to.
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.