MongoDB Backup for Sharded Clusters` is a service provided by `MongoDB Management Service (MMS)` that simplifies the process of backing up a sharded cluster, which presents additional complexity compared to backing up a single database system. The alternative approach involves stopping writes, taking snapshots, and dealing with potential inconsistencies. In contrast, MMS provides consistent snapshots every six hours, utilizing the `oplog` to maintain a secondary node for each shard in the cluster. This service also allows for point-in-time recovery and granular restore points through checkpoint configuration, offering a higher quality snapshot than a do-it-yourself approach without the hassle of orchestrating snapshots.