SANs, or Storage Area Networks, are a way to access multiple data storage different from a NAS or Network Attached Storage. In basic terms, a SAN is a collection of hard drives that are connected together in a single box with multiple PCI cards that transfer data through a fiber optic cable to any computer with a fiber optic PCI card. What makes a SAN unique is that it is not OS dependent like NAS because it uses block level storage.
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