What is a member?
A member is one inventory item inside a SKU Stock Sync group.
Members are the items SKU Stock Sync keeps aligned when they share the same SKU at the same Shopify location.
If a group contains 3 members, that means SKU Stock Sync has found 3 inventory items with the same SKU at the same location.
Why members matter
When one member's inventory changes, SKU Stock Sync checks the related group.
If the group needs syncing, the app can update the other members so the group stays aligned.
Example
If 3 variants all use the SKU GREY-M at your Location A, each matching inventory item is a member of that group.
Member 1: GREY-M at Location A
Member 2: GREY-M at Location A
Member 3: GREY-M at Location A
When the group is synced, SKU Stock Sync can update the members so their inventory stays aligned.
Short answer
A member is one inventory item that belongs to a group.
If a variant is missing from a sync, it may not have been a member of that group at the time the sync ran.