The Matrox M9188 is a multi-display graphics card designed for professional use, such as in control rooms, video walls, and other applications where multiple monitors need to be driven from a single computer. It supports up to eight displays simultaneously and is often used in environments that require high-resolution graphics and stability.

The Matrox M9188 ATX PCIe x16 refers to the physical interface and form factor of the card, which is an ATX-compatible, PCIe x16 (a high-speed interface standard) card. This card is typically used in workstations that need advanced video output capabilities.