When I speak to many photographers and videophiles, one thing seems to irk everyone. It’s the secret code word, decoder ring mystery of what all the number babble on memory cards means and how to know which one to buy. Let’s cut through all the chaff and get to what this stuff actually means, and why you may or may not care. I will note the four most popular card formats, Secure Digital (SDXC), Compact Flash (Now v4), XQD, and CFast 2.0.