Hello silverches - Welcome to the Sony Forums

This camera can save photos and video clips to an SD card - it is most likely just saying that in order to get good performance when saving videos, you should consider purchasing an SD card that is class 4 or higher in terms of its reading and writing speed. If you want to get more information about the official specification of this camera, take a look at the Sony page for this model which can be found at:

http://www.sony.co.uk/product/dsc-w-series/dsc-w570

Regarding memory cards, the camera itself can take SD cards and Memory Stick Duo. However, as you will see on the site, certain types of Memory Stick will not allow you to record movie clips and this may be why the site that you originally found advises viewers to go for an SD card.

Thanks,

Simon