Both S3 and DynamoDB automatically scale as demand dictates. In the case of DynamoDB you can
either configure the on-demand or provisioned capacity mode. With on-demand capacity mode
DynamoDB automatically adjusts the read and write throughput for you
EC2 cannot scale automatically. You need to use Auto Scaling to scale the number of EC2
instances deployed
EBS and RDS do not scale automatically. You must intervene to adjust volume sizes and
database instance types to scale these resources