AWS snapshot vs image

 A snapshot is a backup of an EBS volume. An AMI (Amazon Machine Image) is a clone of the entire EC2 instance including licenses. An AMI created from an EC2 instance includes snapshots of the root volume and any other attached EBS volumes.

You can create an EC2 instance from a snapshot except for systems such as Windows or RedHat where licensing is required. For these types you need to create EC2 instances from an AMI.

Creating an EC2 instance from an AMI that you created is the same as any other AMI.

To create an EC2 instance from a snapshot, you first have to create an Image from the snapshot. Then you can launch the AMI just like other AMIs.

https://stackoverflow.com/questions/47245261/snapshot-vs-images-in-aws