Your environment and how much protection you require, and at which level, will determine the AWS Shield tier that you implement within it. Currently, there are two tiers available:
- AWS Shield Standard: The first tier is freely available to anyone with an AWS account.
- AWS Shield Advanced: The second tier is a premium tier that comes with a range of additional features and protection. However, this comes at an additional cost.
By visiting https://aws.amazon.com/shield/getting-started/, you can see the full list of differences between the two tiers.