ASUS Z790 GAMING WIFI7 LGA 1700 ATX motherboard ...
Motherboards with multiple M.2 slots allow installation of several NVMe SSDs, significantly increasing data transfer speeds and storage capacity.
M.2 - Wikipedia
Traditional motherboards designs were limited in how many M.2 slots they could provide due to two elements: available PCIe lanes and power restrictions.
Motherboard with 2 Graphic Card Slots - Durable & Efficient
This design offers an additional easy to access M.2 slot for fast NVMe storage for motherboards with limited M.2 connectivity.