are standby redo logs mandatory in dataguard?

Hi

In a dataguard configuratiopn,are the standby redo logs mandatory to exist on standby side?

I have a configuration where there are no standby logs .

select * from v$standby_log

no rows returned

Are they only mandatory when you have redo apply configured?

I think when you are applying directly from the transferred archive logs,no standby log is required

Thank You