Amazon security credentials - Amazon General Reference
Services or capabilities described in Amazon Web Services documentation might vary by Region. To see the differences applicable to the China Regions, see Getting Started with Amazon Web Services in China.

Amazon security credentials

When you interact with Amazon, you specify your Amazon security credentials to verify who you are and whether you have permission to access the resources that you are requesting. Amazon uses the security credentials to authenticate and authorize your requests.

For example, if you want to download a protected file from an Amazon Simple Storage Service (Amazon S3) bucket, your credentials must allow that access. If your credentials don't show you are authorized to download the file, Amazon denies your request. However, your Amazon security credentials aren't required for you to download a file in an Amazon S3 bucket that is publicly shared.