# Main Features of Placement Driver (PD)

+ Stores the metadata for the TiKV cluster
+ Generates Global IDs and Transaction IDs
+ Generates a global timestamp TSO 
+ Collects cluster information for scheduling
+ Provides labels to support high availability
+ Provides TiDB Dashboard

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The main features of the PD are as follows:

PD works as the metadata storage for the entire cluster TiKV
- Information regarding the Region and the Key Range mappings, the Region and the TiKV Store mappings are stored in PD.
- For example, the TiDB server obtains route information from PD and then accesses the data in the relevant TiKV.
- Also, including the topology information of the TiKV, the information of label is also stored in PD, which will be described in detail later.

PD allocates global ID and transaction ID
- Global IDs such as the store ID, region ID, peer ID, table ID, and index ID, and transaction ID for distributed transaction are also generated and assigned by Placement Driver.

PD generates a global timestamp TSO
- TSO is a timestamp that guarantees the order of transactions in TiDB cluster.

PD gathers cluster information for scheduling
- The TiKV node periodically reports the status of the cluster to PD, and PD is responsible for scheduling the Region between the TiKV nodes according to the relevant status. The details will be described later.

PD provides TiDB Dashboard services
- In summary, PD is equivalent to the central control center for the TiDB database. In later sections, we will focus on generating global timestamps, TSO, and scheduling features.