It's the standard folder structure for digital cameras.
the top level will always be called "DCIM" which tells your computer (and any other device that supports it) to expect to find digital camera pictures in that folder,
the next folder (100SSCAM in your case) relates to the make of the camera, if you plugged the card into a different camera that would create a folder with a different name, this stops different cameras overwriting each others files if the cards are used in more than one camera.