Do I say PCIe SSD or NVMe SSD? Are all NVMe SSDs PCIe?

The use of PCIe SSD, NVMe SSD, NVMe/PCIe SSD are all common and acceptable. Most people today use NVMe SSD to imply a PCIe SSD (since that is what has existed from 2011 to today) but in the future, NVMe SSDs may also be on other physical interfaces beyond PCIe architecture.