An ATX motherboard is a type of computer motherboard that follows the Advanced Technology eXtended (ATX) standard. It is designed to provide a balance of size, expandability, and performance. Typically measuring 305 mm x 244 mm, ATX motherboards offer multiple slots for RAM, graphics cards, and other components, allowing users to customize their systems. ATX motherboards support various CPU sockets and chipsets, making them compatible with a wide range of processors. They also include features like integrated audio, networking, and multiple USB ports, enhancing connectivity and functionality for both gaming and productivity tasks.