# Overview

+ What is `PD`? `PD` is a component of `TiKV`
+ `PD` has a global view of `TiKV`
  + `Store` status: `Up/Down/Offline/Tombstone/IsBusy ...`
  + Region status: `Region ID/Key Range/Number/Size/Flow ...`
+ As the name indicates, `PD` is responsible for controlling the placement of cluster data

![`smart`](TiDBClusterArchitectureDetail_aa_001_20221005.png)
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