A removable flash memory card format used in cameras, mobile devices, embedded systems, and portable electronics. SD cards are defined by the SD Association and categorized by capacity, bus interface, and speed class.
Capacity Classes:
Speed Classes: C2–C10, U1–U3, V6–V90, E150–E600
Bus Interfaces: Default, High‑Speed, UHS‑I/II/III, SD Express
SD cards are widely used for photography, video recording, mobile apps, and embedded storage.