# Distinguish Between TiDB System Parameters and Cluster Parameters

__*TiDB system configuration*__
__*TiDB system variables*__
__*TiDB cluster configuration*__
__*TiDB cluster variables*__

![left](./student-guide/diagram/DistinguishSystemParametersClusterParameters_en_001_20220617.png)
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Characteristics of system parameters:
- Some of the system parameters are stored in the kv storage of the TiDB database.
- Some system parameters are stored in the TIDB-Server configuration file.
- There is scope.
- It can be modify through the MySQL client.
- Modifications to some parameters do not require a restart to persist.
- This refers specifically to the parameters of TIDB-Server. TiKV and PD are not included.

Characteristics of cluster parameters:
- All parameters are stored in the configuration files of TIDB-Server, TikV-Server, and PD.
- There is no scope.
- The modify must be made through tiUP edit-config and tiup reload.
- You must pass the configuration file on the node before restart the node to take effect.
- Contains parameters for all the configuration files of TIDB-Server, TikV-Server, and PD.