Choosing Between `decodeUnknown` and `decodeUnknownSync` in Effect Typescript

when do I use decodeUnknown vs the Sync method?

Effect.flatMap(Schema.decodeUnknown(schema))
Effect.map(Schema.decodeUnknownSync(schema))

Effect.flatMap(Schema.decodeUnknown(schema))
Effect.map(Schema.decodeUnknownSync(schema))

I think these are equivalent but idk when id pick one or the other

Choosing Between `decodeUnknown` and `decodeUnknownSync` in Effect Typescript - Effect Community