You might find the explanation in TFA helpful:
> "A battle royale lobby has just 100 players, which fit within a single compute shard.
> "But Fortnite is much more than just battle royale. A huge number of Fortnite players are on custom game modes made by people outside of Epic Games. It’s easy to imagine game modes having a few thousand players which can’t fit within a single shard. How do you scale to handle all that game state, correctly?
> "Software transactional memory is at the core of Verse. Computation is categorised by transactions and ability to rollback. The goal is to make it easy to write working software across multiple servers. A big goal; we don’t often see programmers do that successfully!"