Block-level storage is a concept in cloud-hosted data persistence where cloud services emulate the behaviour of a traditional block device, such as a physical hard drive.
A file system must be applied on top of the block-level storage to map 'files' onto a sequence of blocks.
[2] Cloud block-level storage will usually offer facilities such as replication for reliability, or backup services.
These operate at a higher level of abstraction and are able to work with entities such as files, documents, images, videos or database records.
[8] Even block-storage is now seen as distinct servers (thus NAS), rather than the previous array of bare disks.