Group

"Group" may refer to a:

"Bundle" - items are released together, acquiring the bundle or package gifts the player all items in the package at once.

"Collection:" Items are clearly related but methods of acquisition might be a bit different and don't qualify for other types of groups. Generally applies to Prize Box items.

Family: A user-based grouping of entities that share similar themes, like "food."

Set: items are very obviously related because they share similar names, stats, and abilities.