Authentication type
Controls where credentials are loaded from.
Saved S3 credentials
Use saved Access key ID and Secret access key.
Load from credentials file
Load the access key and secret access key from an AWS SDK credentials or AWS CLI config file. If provided, security tokens will be used for time limited credentials. The default credentials file is %UserProfile%\.aws\credentials 
or ~/.aws/credentials 
, but Beyond Compare will use the AWS CLI "config" file if necessary and does respect the AWS_SHARED_CREDENTIALS_FILE and AWS_CONFIG_FILE environment variables if they're present. The profile should be one that exists within that file. If left blank, "default" is used.
Load from environment variables
Load the access key, secret access key, and security token from AWS_* environment variables. It will first check for the AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY, and AWS_SESSION_TOKEN variables. If those do not exist, it will select a profile from the default credentials file (as above). The AWS_PROFILE variable can be used to select a non-default profile.
Bucket (optional)
This can be used to select a bucket in case you don't have permission to list all buckets.
The Description can include any text you want.
