About Bucket Policies
Bucket policies define who can access your bucket and what actions they can perform. The Resource uses standard bucket ARN format.
The Principal is a principal ARN — a user (arn:aws:iam::000000000000:user/alice), a role, which covers every session of it (arn:aws:iam::000000000000:role/reader), one assumed-role session (arn:aws:sts::000000000000:assumed-role/reader/session), or the account itself (arn:aws:iam::000000000000:root), which delegates to the account’s IAM rather than granting on its own. "*" names everyone. Wildcards are not allowed inside an ARN.
The Principal is the access key of the user account.