Memory Cards…

Compact Flash (CF Card) - is regarded as the memory card for the professional photographer. These are physically much bigger than SD cards, and less commonly used. They often have bigger capacities and can run at very high speeds.

Secure Digital - is the basic format of the SD card. They usually perform well, but not as fast as other SD cards. These are limited to 4GB; anything above would be an SDHC card.

Secure Digital High Capacity (SDHC) was created to meet the high demands for high-definition photography and video. Any SD card above 4GB of memory is an SDHC card. Currently, these are limited to 64 GB, and anything higher is classed as an SDXC card.

Secure Digital Extended capacity (SDXC) is essentially a beefed-up SDHC card. These cards start at 64 GB and can reach a size of 2 TB.

Micro Secure Digital (MicroSD) is a micro version of the SD card, as the name indicates. It has the same storage as the SDHC card, storing up to 32 GB of data - and can transfer up to 10 MB per second.

Extreme Digital Picture Card (XD) is a removable le flash memory, designed for use in digital camera. It has a compact size.

Compatibility - Memory cards will only work if they are compatible with the proposed camera.

UDMA Rating (Ultra Direct Memory Access rating) Memory cards are graded for 0-7, with 0 being the lowest and 7 the highest performance. Not all devices support all speeds, so check before you buy.

Reading Speed - This is the rate at which the memory card can record and store the images you capture. This is the most critical speed.

Micro SD cards can be used as standard SD cards when used with an adapter.