SDHC (Secure Digital High Capacity) and SDXC (Secure Digital Extended Capacity) are designations given to larger-capacity SD memory cards and can apply to full-size, mini and micro SD variations. SDHC cards support capacities up to 32GB and come pre-formatted with the FAT32 file system, while SDXC cards can theoretically support up to 2TB – although 128GB versions are the largest currently available. These come pre-formatted with the exFAT file system and also enable greater data transfer speeds. You can manually re-format these cards to FAT32 if you need to use them on a system which doesn’t support exFAT.

It’s important to note the distinction between these card formats as not all devices can handle SDHC or SDXC cards. You should therefore check your device for compatibility before purchase.