What is a group?
A group is a set of inventory items that share the same SKU at the same Shopify location.
SKU Stock Sync uses groups to decide which items should have matching inventory.
A group is also called a SKU/location group because both the SKU and Shopify location need to match.
How groups are created
SKU Stock Sync groups inventory items when they match on both:
SKU
Shopify location
Same SKU alone is not enough. Same location alone is not enough. Both need to match.
Example
If 3 variants use the SKU GREY-M at your Shop location, SKU Stock Sync can treat them as one group.
If the same SKU also exists at another location, that becomes a separate group.
The same SKU at different Shopify locations is not one shared group. Each location is handled separately.
Why groups matter
When inventory changes for one member of a group, SKU Stock Sync checks whether the group needs to be synced.
If the group becomes due, the app can process the group during scheduled syncing or manual syncing.
Short answer
A group is the set of matching inventory items SKU Stock Sync uses when syncing shared stock.
If two variants should not share stock, they should not use the same SKU at the same Shopify location.