User1: RBAC -
RBAC is used as the Key Vault access control mechanism for the management plane. It would allow a user with the proper identity to:
- set Key Vault access policies
- create, read, update, and delete key vaults
- set Key Vault tags
Note: Role-based access control (RBAC) is a system that provides fine-grained access management of Azure resources. Using RBAC, you can segregate duties within your team and grant only the amount of access to users that they need to perform their jobs.
User2: A key vault access policy
A key vault access policy is the access control mechanism to get access to the key vault data plane. Key Vault access policies grant permissions separately to keys, secrets, and certificates.
References:
https://docs.microsoft.com/en-us/azure/key-vault/key-vault-secure-your-key-vault