Secure Digital (SD) cards are small memory card widely used in many portable devices nowadays.
The devices that use SD memory cards include digital cameras, mobile phones, PDAs, digital camcorders, GPS navigators, netbooks, media players, etc.
SD memory cards come in 3 different physical sizes:
- Standard SD - 32 × 24 × 2.1 mm
- miniSD - 20 x 21.5 x 1.4 mm
- microSD - 15 x 11 x 1.0 mm
In terms of storage capacity, there are also 3 types:
- Standard SD - up to 4GB
- High Capacity (SDHC) - 4GB to 32GB
- Extended Capacity (SDXC) - 32GB to 2TB
In terms of writing speed, you might find the SD memory cards labelled as:
- Class 2: 16 Mbps (2 Megabytes ps)
- Class 4: 32 Mbps (4 Megabytes ps)
- Class 6: 48 Mbps (6 Megabytes ps)
- Class 10: 80 Mbps (10 Megabytes ps)