The Relationship Between Block Public Access and Bucket Policy for S3 Public Access

Introduction

I checked the following four statuses for S3 public access and will summarize them.

Private bucket and objects
Objects can be made public
Public
Authenticated users of this account only

1. Private Bucket and Objects

When in the following state, Private bucket and objects is displayed:

Block public access is ON
No explicit access permitted in the bucket policy

2. Objects Can Be Made Public

When in the following state, Objects can be made public is displayed. At first I thought this meant public access was possible, but it seems an explicit bucket policy change is required. Even though the Japanese text implies public access is possible, access is actually not possible.

Block public access is OFF
No explicit access permitted in the bucket policy

3. Public

When in the following state, Public is displayed:

Block public access is OFF
Explicit access is permitted in the bucket policy

Example:

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Sid": "PublicReadGetObject",
            "Effect": "Allow",
            "Principal": "*",
            "Action": [
                "s3:GetObject"
            ],
            "Resource": [
                "arn:aws:s3:::s3-public-test-1/*"
            ]
        }
    ]
}