The NMP is an extensible multipathing module that ESXi supports by default. You can use esxcli storage nmp to manage devices associated with NMP and to set path policies.
The NMP supports all storage arrays listed on the VMware storage Hardware Compatibility List (HCL) and provides a path selection algorithm based on the array type. The NMP associates a set of physical paths with a storage device (LUN). An SATP determines how path failover is handled for a specific storage array. A PSP determines which physical path is used to issue an I/O request to a storage device. SATPs and PSPs are plug-ins within the NMP.