Block storage is a type of data storage technology that divides data into blocks of equal sizes. Each block is stored separately and given a unique identifier, without any higher-level metadata such as data format, type, and ownership. Block storage is used to store data files on storage area networks (SANs) or cloud-based storage environments. It is often used for transactional, mission-critical, and I/O intensive applications, such as relational or transactional databases, time series databases, containers, boot disks, and hypervisor file systems.

Block storage is different from other types of storage, such as object storage or file storage, which operate at a higher level of abstraction and are able to work with entities such as files, documents, images, videos, or database records. Block storage is best suited for static files that aren’t changed often because any change made to a file results in the creation of a new object.

Block storage allows developers to set up a robust, scalable, and highly efficient transactional database. It also offers an impressive level of flexibility because it can be accessed by different operating systems as mounted drive volumes and has the ability to use operating system–specific file systems. Block storage is usually deployed in storage-area network (SAN) environments and must be tied to a functioning server.

Some examples of block storage include Amazon EBS (elastic block store) , Oracle block storage, and Cloudflare block storage.