Breaking down SAN and NAS.

Storage area network (SAN) is a high-speed dedicated network of servers and shared storage devices. A SAN provides storage and enables centralized data management. It meets the storage demands efficiently with better economies of scalability and also provides effective maintenance and protection of data. Network attached storage (NAS) is a high-performance file sharing and storage device. NAS allows its clients to share files with an IP address.  In other words SAN and NAS both are network technologies that allow you to manage the disk storage on your network. However, NAS is a much simpler and less expensive than SAN.

            Using network attached storage actually reduces the task of adding storage to a network because it eliminates the priority of configuring a network operating system for routine file sharing tasks. A storage area network is designed for managing very large amounts of network storage. A SAN contains three components: storage devices (which could be hundreds of them), a separate high-speed network (normally fiber-optic) that directly connects the storage devices to each other, and on or more SAN servers that connect the SAN to the local area network. The SAN server manages the storage devices attached to the SAN and allows users of local area networks (LAN) to access the storage.

            A NAS is dedicated specifically to serving files. The hardware is optimized it could have more network connections. Also its operating system is slim down so that it is dedicated to sharing files and not performing other functions. People use this device to store files that is accessible to other people. NAS uses Linux, Windows, Mac share data, large files and backup locations. Typically with SAN, servers access specific parts of the storage. Clients of SAN have storage utilization of moving and reallocating storage. SAN also uses iSCSI and Fibre channel. This is the protocol used to access your storage. iSCSI has a lower cost that comes with a lower performance. Fibre Channel has a higher cost with better performance. 

If you need more of an overview check out this video!