At the money binary option

From Binary Options Trading Wiki

'At the money' is a professional term to describe an option trade in which the price during expiration is identical to the level at which the option was bought-In such a scenario the initial investment amount is fully returned to the customer. For example, if the customer has made a $100 ‘Call’ investment on Google stocks at a level of 305.5, with an expiry time of 15:00 and the level at the expiry time was 305.5, the full investment amount is returned to the customer, and the customer's account will be credited with $100.

'At the money' is one of the three possible condition in options trading other than: in the money and out of the money