Aliases in the serverless service provided by this cloud provider give developers the ability to create mutable references to specific versions of a function. This feature is essential for automating deployment testing and promoting code through different environments without needing to change the function references in the deployment scripts or other automation tools. CodeDeploy is primarily used for automated deployment of applications to a variety of compute services, Artifact repositories are used for storing build outputs like binaries or libraries, and Services Catalog is used for organizing and governing services across an enterprise but they don't offer mutable references to function versions.