SAN is especially important for bandwidth-intensive applications such as database,imaging and transaction processing. The distributed architecture of SAN enables is to offer higher levels of performance and availability than any other storage medium. The benefit is that large number of users can simultaneously access data without creating bottlenecks on the local area network and servers.
DAS, on the other hand, is Ideal for localized file sharing in environment with a single server or a few server, for example, small business or department and work groups that do not need to share information over long distance or across an enterprise. Small companies traditionally utilize DAS for file serving and e-mail, while larger enterprises may leverage DAS in a mixed storage environment that includes NAS and SAN.
NAS is an ideal choice for organizations looking for a simple and cost- effective way to achieve fast data access for multiple clients at the file level. Implementers of NAS benefit from performance and productivity gains