Next choose the primary (required) and secondary (optional) hard disk drives for your new desktop.
The primary hard drive is a solid state drive (SSD), which is significantly faster, smaller, lighter, more energy-efficient and less prone to damage than a mechanical hard drive.
Choose one (required):
The optional secondary hard drive is a mechanical hard drive, which offers greater storage capacity. If both speed and storage capacity are important, you may select one of each type and the OS will be installed onto the SSD while the home directory (your data) will be mounted on the mechanical drive.
Choose one (optional):