Which AWS service is best suited for long-term data storage at a lower cost?

Amazon S3 Glacier is specifically designed for long-term data storage at a lower cost, making it the best choice for this purpose. It offers a highly durable, low-cost storage solution for data that is infrequently accessed and can tolerate longer retrieval times. S3 Glacier is optimized for archiving data, allowing organizations to store large amounts of data economically while also providing options to access the data when necessary, albeit at a slower retrieval speed compared to standard storage options.

In contrast, other services such as Amazon S3 Standard, while providing durability and availability, cater to a different use case involving frequently accessed data, which typically comes with a higher cost. Amazon EBS (Elastic Block Store) is more suitable for block-level storage for EC2 instances and is not primarily focused on cost-effective long-term data storage. Amazon RDS (Relational Database Service) is specifically designed for managing relational databases and not intended for long-term data storage. Thus, S3 Glacier stands out as the optimal solution for long-term, low-cost data storage.