Secure Digital (SD) 8GB Memory card. SD memory cards are the latest generation memory devices that offer an incredible combination of high storage capacity, fast data transfer rates, great flexibility and excellent security in a memory card about the size of a postage stamp! Based on nonvolatile memory components and encased in a protective molding they do not require power to retain the information stored on them. Since they are based on solid-state components they have no moving parts to skip or break down making them highly reliable.