Often, if you omit the name attribute from a resource, CloudFormation will generate a name for you. This can result in weird-looking resource names, but it will increase the replayability of your template. Using AWS::S3::Bucket as an example, if you specify the BucketName parameter but don't ensure its uniqueness, CloudFormation will fail to execute your template the second time around because the bucket will already exist. Omitting BucketName fixes this. Alternatively, you may opt to generate your own unique name each time the template is run. There's probably no right or wrong approach here, so just do what works for you.