What type of storage device does an SD card refer to?

An SD card refers to a Secure Digital Card, which is a non-volatile storage medium used for storing digital data. This type of card is widely used in various devices, including cameras, smartphones, and tablets, because of its compact size and ability to hold a substantial amount of data. The “secure” aspect of its name implies that it includes built-in security features that protect the stored content, making it a reliable choice for users who need secure data storage solutions. Other options, while they contain some of the terms found in the correct answer, do not accurately reflect the recognized term or standard used in the industry.