Download all the contents of an S3 bucket to your local current directory using below commands:
aws s3 sync s3://bucketname .
s3cmd sync s3://bucketname .
Use the below command to download all the contents of a folder in an S3 bucket to your local current directory:
aws s3 cp s3://bucketname/prefix . --recursive
Click Here to see how to download multiple files from an S3 bucket.