A Storage Area Network (SAN) is primarily designed to provide access to consolidated, block-level data storage, which is crucial for enhancing storage devices, such as disk arrays and tape libraries, that are accessible to servers so that the devices appear to the operating system as locally attached devices. SAN is mostly used in data centers to enhance storage performance and redundancy. The other options refer to functions that are more characteristic of network-attached storage (NAS), which uses file-based data storage, or direct server integrations, which are not the primary purpose of SANs.