"Coin-operated" refers to machines or devices that require coins to function. These machines are commonly found in public places, such as laundromats, arcades, and vending machines. Users insert coins to activate the machine, allowing them to access services or products. The concept of coin-operated devices dates back to the late 19th century, with early examples including cigarette vending machines. Today, many coin-operated machines have evolved to accept various forms of payment, including credit cards and mobile payments, but the traditional coin mechanism remains popular for its simplicity and ease of use.