Then can be used for this, of course, but high-capacity memory cards are cheap these days, and storage space isn't the problem it was.
Some cameras use dual slots to offer support for two different card formats. This Nikon D-SLR can take both SD cards and Compact Flash.
Instead, you can use the two card slots to store different types of data which you want to keep separate. Depending on whether the camera supports it, you could do the following:
• Save photos to both cards at the same time so that you always have a backup in case one memory card fails or gets lost
• Use one to store RAW files and the other to store JPEGs (for cameras which offer simultaneous RAW/JPEG shooting)
• Use one card to save photos and the other to save movies
