nvm slotThe ‘Key M’ or ‘M key’ slot is specifically for PCI-E SSDs aka NVME SSDs which are currently the fastest SSD type that one can buy. The ‘Key B’ slot is for M.2 SATA SSDs.nvm is a version manager for node.js, desned to be installed per-user, and invoked per-shell. nvm works on any POSIX