What is a key feature of a contactless reader?

A key feature of a contactless reader is that it can communicate via radio waves with the card. This capability allows the reader to interact with contactless payment cards or mobile devices that support near field communication (NFC) technology without the need for physical contact. The communication occurs when the card is held within a short range of the reader, usually a few centimeters. This wireless interaction enhances the convenience and speed of transactions, making it a preferred choice in modern payment environments.

The other options focus on characteristics that are not applicable to contactless technology. For instance, requiring a physical connection, processing only magnetic strip cards, or needing to be connected to a computer contradict the fundamental aspects of contactless payments, which prioritize ease of use and quick transaction capability.