@Tarun Malik Welcome to Microsoft Q&A Forum, Thank you for posting your query here!
Azure Blob Storage is a PaaS (Platform as a Service) offering. Azure Storage consists of multiple services, some can be classified as PaaS, and some as IaaS https://azure.microsoft.com/en-in/overview/what-is-iaas/
Blob stroage is one of the functionality of the Azure Stroage , For more details refer to Azure Storage Data Services
Azure Storage Services can be categorized under both IaaS and PaaS, depending on the use case.
They are IaaS since Azure Storage Services provide the fundamental building blocks for cloud-based applications and services, where you get raw storage capacity (like a hard drive in the cloud) and are responsible for how you manage and utilize that capacity.
They are PaaS since Azure handles all the infrastructure management, maintenance, and scalability, allowing users to focus on how they utilize the storage rather than managing the underlying hardware or OS.
But according to the old definition and used cases you think most if the services under Azure Storage Services can be count under IaaS but some of them are more aligned with PaaS definiton.
Please let us know if you have any further queries. I’m happy to assist you further.
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