The Supercard SDHC ONE is a slot1 card, it goes in the DS games slot. You can only play DS games and homebrew on it, no GBA games. Just drag-and-drop files to the card and go.
The Supercard LITE is a slot2 card. It can play DS and GBA games, homebrew, etc. But you have to patch each game for the card using their PC patcher program. Plus, to play DS games, your DS would either have to be flashed, or have some kind of PassMe device to boot the SC LITE in DS mode.