Which Azure service is primarily used for low-cost archival storage?

Azure Archive Storage is specifically designed for low-cost archival storage, making it the ideal choice for scenarios where data is infrequently accessed but needs to be retained for long periods, such as compliance or backup purposes. This service offers a significant reduction in storage costs compared to other storage types, while still ensuring that the data can be retrieved when necessary, albeit with some latency involved in the retrieval process.

In contrast, Azure Blob Storage encompasses several tiers, including a hot and cool tier, but does not provide the same level of cost efficiency for archival data as the Archive Storage tier. Azure Disk Storage is mainly intended for persistent disk storage for virtual machines and applications, and it is optimized for high-performance workloads, making it unsuitable for archival purposes. Azure Table Storage is designed for structured NoSQL data and is utilized for different use cases, primarily focused on storing non-relational data rather than archiving. Thus, Azure Archive Storage is the dedicated service tailored to fulfill the needs of low-cost archival storage efficiently.