What distinguishes inline policies from other policy types in AWS?

Inline policies are unique because they are directly embedded into a single identity, such as a user, group, or role in AWS Identity and Access Management (IAM). This means that the policy is tied to that specific entity and exists only in that context. When you attach an inline policy to an IAM user, for example, the permissions granted apply solely to that user. This provides a granular level of permission control, as the inline policy's lifecycle is linked directly to the identity it is associated with. When the user is deleted, the inline policy is also automatically deleted, ensuring that permissions remain tightly coupled with the identity.

While other policy types, such as managed policies, can be applied to multiple identities and reused across different entities, inline policies are exclusive to one identity. This exclusivity makes them ideal for specific, custom permissions that do not need to be shared or used elsewhere in your AWS environment.