Barrier Option
Also called: barrier, knock-in put, knock-out, in-out-parity, in out parity
An option that switches on or off if the price touches a set level — a 'knock-in' comes alive, a 'knock-out' dies. Cheaper than a vanilla option because that trigger can cancel the payoff entirely.
Where this is taught
Definitions are the trailer. These free levels turn Barrier Option into something you play — one bite-size lesson, with worked examples, a quiz and XP.