People who are familiar with Everpure FlashArray terms will recognize this name-the FlashArray also uses the term Protection Groups. It is important to note that these are related mechanisms (in that they both have to do with replication) but they are not the same in SRM vs FlashArray.
An SRM protection group includes one or more volumes that must be failed over together. A volume can only be in one SRM protection group at a time.
A FlashArray protection group is a replication and/or local snapshot policy that can be assigned to one or more volumes on a FlashArray. Many volumes can be assigned in a FlashArray protection group and a volume can be in many FlashArray protection groups.