Short for Secure Digital High Capacity, SDHC is a type of flash memory card based on the SDA 2.00 specification. The SDA 2.00 specification enables SD cards to reach higher capacities from 4GB to 32GB, and growing. SDHC uses a new technology, and as such these cards are not backwards compatible with SD format devices. SDHC uses a defined 3 speed class system to help consumers with the different data transfer speed (DTS) and performance minimum requirements;
- Class 2: minimum sustained DTS of 2MB/sec
- Class 4: minimum sustained DTS of 4MB/sec
- Class 6: minimum sustained DTS of 6MB/sec
The SD Specification Version 2.0 for the SDHC memory card was established by the SD Card Association (SDA).