An amount of storage capacity presented to a host to format with its own file system is:

A LUN (Logical Unit Number) represents a logical disk drive or section of a disk drive, which is presented by a storage array, such as a SAN, to a host server. The host server then treats this LUN as a local hard drive, allowing it to be partitioned, formatted with a file system, and used for block-level storage.

A 'zone' typically refers to a Fibre Channel zoning configuration, which segments a Fibre Channel fabric to control which devices can communicate with each other, not a unit of storage capacity.

A 'share' usually refers to a network share (e.g., SMB/NFS share), which provides file-level access over a network, not a block-level volume presented to a host for formatting.

An 'export' is a term often used in network file systems (like NFS) to describe a directory or file system made available to clients, similar to a share, and typically provides file-level access.