Hello Arun Maharana,
the KMS client product key is used to activate Windows operating systems through a KMS server. This key is typically used in enterprise environments where multiple computers need to be activated.
However, it is important to note that the KMS client product key is not a public license key and should not be shared outside of your organization. It is intended for use only within your organization's network.
I hope this information helps.
Kind regards,
Lei