Elastic and Amazon OpenSearch Service both utilize data tiers to optimize data storage and management, but they differ in terminology and functionality, which can lead to confusion. Elastic's data tiers include Hot, Warm, Cold, Frozen, and Snapshots, each optimized for different access and storage needs, while Amazon OpenSearch Service offers Hot, OR1, UltraWarm, and Cold tiers. Elastic allows for more flexibility and efficiency with features like searchable snapshots and the ability to scale with replicas in the Warm tier, whereas Amazon OpenSearch Service has limitations such as no replicas in OR1 and fewer configuration options for UltraWarm nodes. Both platforms support Graviton2-based instances for performance and cost efficiency, but Elastic provides a broader range of instance types across multiple cloud providers. Understanding these distinctions is crucial for making informed decisions about data management strategies, emphasizing the importance of looking beyond naming conventions to grasp the underlying capabilities of each tier.