DNS hosting service is better when the provider has multiple servers in various geographic locations that minimize latency for clients around the world.
DNS can also be self-hosted by running DNS software on generic Internet hosting services.
A number of sites offer free DNS hosting, either for second level domains registered with registrars which do not offer free (or sufficiently flexible) DNS service, or as third level domains (selection.somedomain.com). These services generally also offer Dynamic DNS. Free DNS typically includes facilities to manage A, MX, CNAME, TXT and NS records of the domain zone. In many cases the free services can be upgraded with various premium services.