(1) An array of elements in row and column form. See
x-y matrix and
mathematical matrix.
(2) For the instant message protocol, see
Matrix protocol.
(3) For the barcode, see
matrix barcode.
(4) For early printers, see
dot matrix printer.
(5) For the A/V router, see
matrix router.
(6) For digital audio, see
matrixed channel.