Complex sentence: Typically, ALSA supports up to eight "cards", numbered 0 through 7; each card is a physical or logical kernel device capable of input, output, or, and card number 0 is used by default when no particular card is specified.
Split into simpler sentences: Typically, ALSA supports up to eight "cards", numbered 0 through 7; each card is a physical or logical kernel device capable of input, output, or, and. A card has "devices", numbered starting at 0;; device number 0 is used by default when no particular device is specified.