Definition: Secure Digital eXtended Capacity (SDXC) is a type of flash memory card used in digital cameras to store data about images. SDXC is an updated version of SD memory cards, and SDXC cards have more memory capacity, allowing for storing up to 2 terabytes (TB) of data on a single card. However, most of the early SDXC cards contain capacities of 64 GB (gigabytes) of data.

SDXC cards are slightly rectangular, with one corner cut at a 45-degree angle, and they look almost exactly like SD cards.

SDXC cards measure 24 mm by 32 mm by 2.1 mm (0.94 x 1.26 x 0.08 inches).

Another type of SD card, SDHC (SD high capacity), allows storage capacities at 4 GB and beyond. SD cards are limited to 2 GB. Some older digital cameras that use SD cards cannot read SDHC or SDXC cards.