Mini-STX, short for Mini Socket Technology Extended, is a small form factor motherboard specification designed for compact and space-constrained computing systems. It is an extension of the Mini-ITX form factor, which is already known for its small size. Mini-STX takes this compactness to the next level, measuring approximately 5.5 inches square (140mm x 147mm). This reduced size makes them ideal for building ultra-compact PCs and embedded systems. Mini-STX systems are well-suited for various applications, including digital signage, point-of-sale systems, and other space-sensitive computing scenarios.