The ECS instance you created is your own resource. By default, you have full operation permissions on your resources, and you can use all APIs described in this document to operate on your resources.
You can use your Alibaba Cloud account to create RAM users, and an unauthorized ram user cannot operate on resources of the Alibaba Cloud account. You need to grant the permission to the RAM user to operate on resources of the Alibaba Cloud account by the RAM authorization.
Skip this section if you do not need to grant an RAM user to access ECS instance resources in an Alibaba Cloud Account. Skipping this section does not affect your understanding and usage of the ECS API.