Active-matrix is a technology used in LCD displays, such as laptop screens, and flat screen monitors. It uses a matrix of thin film transistors (TFTs) and capacitors to control the image produced by the display. The brightness of each pixel is controlled by modifying the electrical charge of the corresponding capacitors. Each pixel's color is controlled by altering the charge of individual capacitors that emit red, green, and blue (RGB) light.
The term "active-matrix" refers to the active nature of the capacitors in the display. Unlike a passive-matrix display, which must charge full rows of wires to alter individual pixels, an active-matrix display can control each pixel directly. This results in a significantly faster response time, meaning the pixels can change state much more rapidly. In practical terms, an active-matrix monitor can display motion and fast-moving images more clearly than a passive-matrix display can. The fast switching of TFTs also prevents the "ghosting" of the cursor that is common on passive-matrix screens.
Since active-matrix technology provides individual control of each pixel, active-matrix screens typically exhibit more even brightness and color across the screen than passive-matrix displays. Because of the multiple advantages of active-matrix technology, most modern computer monitors, laptop screens, and LCD televisions use active-matrix screens.