Replication Lag
In plain terms
The delay before replicas reflect the primary's latest data.
Going deeper
Replication lag is the time it takes for changes on a primary database to appear on its replicas, causing temporary staleness. Reads from replicas may be behind.
Under the hood
Async replication causes lag; reading lagged replicas can show outdated data, a consistency concern.
Examples
Read replicas, async replication, stale reads, database scaling, consistency.
Think of it like...
Like branch offices receiving updated memos a few minutes after headquarters.