An ATX motherboard is a type of computer motherboard that follows the Advanced Technology eXtended (ATX) standard. It provides a layout for connecting various components, such as the CPU, RAM, and graphics card. The standard size of an ATX motherboard is 305 mm x 244 mm, allowing for multiple expansion slots and ports. ATX motherboards are popular in desktop computers due to their versatility and expandability. They typically feature several PCIe slots for additional hardware, multiple SATA connectors for storage devices, and various input/output ports for peripherals. This design makes them suitable for gaming, workstations, and general computing tasks.