Can I use a 3 Gbits SATA hard drive with a 6 Gbits SATA port?

Can I put an NVMe ssd in the SATA 3 slot? sata 3 slot It offers a maximum data transfer rate of 6 Gbps, equivalent to approximately 600 MBs SATA III is backward compatible with SATA II and SATA I, allowing SATA sata 3 slot Mounting frame for inch SATA hard disk and SSD; Add another internal inch SATA HDDSSD to your computer; Suitable for almost all SATA optical drive

sata m2 slot PCI x4 If that's correct, I presume I can't connect most SATA III controller cards into either of the standard PCI slots?