An S3 ACL is a sub-resource that’s attached to every S3 bucket and object. It defines which AWS accounts or groups are granted access and the type of access. When you create a bucket or an object, Amazon S3 creates a default ACL that grants the resource owner full control over the resource.Click to see full answer. Accordingly, does bucket policy override ACL?2 Answers. Bottom line: 1) Access Control Lists (ACLs) are legacy (but not deprecated), 2) bucket/IAM policies are recommended by AWS, and 3) ACLs give control over buckets AND objects, policies are only at the bucket level.Similarly, what is the difference between bucket policy and ACL? There are two types of ACLs available when leveraging S3: Bucket and Object. Bucket ACLs allow you to control access at a bucket level, while Object ACLs allow you to control access at the object level. Also asked, what is s3 bucket policy? A bucket policy is a resource-based AWS Identity and Access Management (IAM) policy. You add a bucket policy to a bucket to grant other AWS accounts or IAM users access permissions for the bucket and the objects in it. Object permissions apply only to the objects that the bucket owner creates.How do I give someone access to my s3 bucket? How To Grant Access To Only One S3 Bucket Using AWS IAM Policy Click on “My Account/Console” and select “Security Credentials”. Select “Continue to Security Credentials”. Select “Policies” on the left menu, then click “Create Policy”. Select “Create Your Own Policy”. Fill out the “Policy Name”, “Description” and “Policy Document” fields.