What is the definition of a matrix?

The most common example of an active matrix display contains, besides the polarising sheets and cells of liquid crystal, a matrix of thin-film transistors (TFTs) to make a TFT LCD. These devices store the electrical state of each pixel on the display while all the other pixels are being updated. This method provides a much brighter, sharper display than a passive matrix of the same size. An important specification for these displays is their viewing-angle.