Clarification on the term 'SBs'

[Beedgehog]

Hey!

I would have said this somewhere else but there wasn't anywhere else.

I am having extended trouble comprehending what 'SBs' means. It would be amazing to have clarification on what it means on the mod page, etc.

Also if anyone could clarify for me down below, that would be superb!

Thank you very much!

[shadeydo]

Shulker boxes full of items