hdd slot - Can I have 2 SSD drives in my pc? And can I also put one ... 888 dragons slot review

My question is, is it possible to have 2 SSD drives (C and D-drive) and put one of them into an HDD slot? And is it possible to have a SSD drive in a HDD slot.

Thiết bị lưu trữ DAS TerraMaster D5-300C ; Disk Slot Number · 5 ; Compatible Disk Types · 3.5" SATA HDD, 2.5" SATA HDD, 2.5" SATA SSD ; File System · FAT 32, FAT 16, ...

Màn hình, 17.3" FHD (1920×1080) IPS, 144Hz ; Ổ cứng SSD / Ổ cứng HDD, 512GB SSD NVMe M.2 PCIe Gen 3 x 4 / 1 slot HDD 2.5' ; Lan / Wireless Lan, Gigabit Ethernet / ...