Secure Digital (SD)

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:

• SD: Up to 2 GB
• SDHC: >2 GB to 32 GB
• SDXC: >32 GB to 2 TB
• SDUC: >2 TB to 128 TB

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.