Depends on the thing you're replicating and the technology you use. If you're replicating a database you get a bunch of 'log' files containing all the changes i

Depends on the thing you're replicating and the technology you use. If you're replicating a database you get a bunch of 'log' files containing all the changes in chronological order. While you could throw those away after filling a single replica database you also can keep them and use them to recover a database snapshot from a while ago. You're not going to get data that recent with only full backups.