A dot matrix is a 2-dimensional patterned array, used to represent characters, symbols and images. Every type of modern technology uses dot matrices for display of information, including cell phones, televisions, and printers. They are also used in textiles with sewing, knitting, and weaving.

An alternate form of information display using lines and curves is known as a vector display, was used with early computing devices such as air traffic control radar displays and pen-based plotters but is no longer used. Electronic vector displays were typically monochrome only, and either don't fill in the interiors of closed vector shapes, or shape-filling is slow, time-consuming, and often non-uniform, as on pen-based plotters.

In printers, the dots are usually the darkened areas of the paper. In displays, the dots may light up, as in an LED, CRT, or plasma display, or darken, as in an LCD.

In the context of printers, the term mainly refers to low-resolution impact printers, with a column of 8, 9 or 24 "pins" hitting an ink-impregnated fabric ribbon, like a typewriter ribbon, onto the paper. It was originally contrasted with both daisy wheel printers and line printers that used fixed-shape embossed metal or plastic stamps to mark paper.