In SQL Server for Replication when recovery model is not very important then how it saves the transactions and also keeps the secondary instance in sync?
I tried to check on msdn and found

> Replication functions properly using any of the recovery models:
> simple, bulk-logged, or full. Merge replication tracks change by
> storing information in metadata tables. Transactional replication
> tracks changes by marking the transaction log, but this marking
> process is not affected by the recovery model

but I didn't get the concept for SIMPLE Recovery Model. And if the T-logs gets copied before checkpoint then what if someone manually executes checkpoint?