EC2 is essentially a virtual server in the cloud. It can be available within minutes after setting it up. Compare that to how long it would take to provision and prepare a physical server in your own datacenter. Even ordering it and awaiting initial configuration and shipment can take weeks. General knowledge about EC2 is one of the key categories in the AWS Certified Cloud Practitioner exam.
S3 is object-based flat file unlimited storage. It's unlimited, but that doesn't mean we should throw files up there without thinking -- storage still costs money. It's not block-based, so it's not meant for storing operating systems or live databases. But any type of file can be stored (including database file backups), and each can be from 0 bytes up to 5 TB. General knowledge about S3 is one of the key categories in the AWS Certified Cloud Practitioner exam.
One of the first things we'll do after creating an AWS account is add users and groups via the IAM console. We will initially do this as the "root" account user. But be careful -- root accounts are not restricted in any way. Therefore, I strongly recommend following the Security Status checklist FIRST when visiting the IAM console.
12Page 2 of 2