what is the performance for DNS server?

[hosting coupons]

i note some hosting provider will offer the DNS server, i am wondering what's used for and its advantages?

[Saad Host]

Performance DNS can provide you with a hassle-free way to manage your DNS needs. From the management of one server to hundreds across the world using our custom interface, you can easily and in real-time, change the IP addresses of your servers. Within five minutes.

[miss.netrookie]

DNS servers allow standard Internet users to use Internet resources without having to remember port numbers and IP addresses. Even similar services, such as different areas of the website, may be hosted at different IP addresses for security reasons. This allows users to memorize simple URL addresses as opposed to complex, nonintuitive lists of IP addresses and port numbers. This also allows private servers made by home users to be freely available yet somewhat shielded from having their IP address publicly known.