Note: This tutorial assumes you've already followed the NetBSD on SDF VPS tutorial to set up networking, the time zone and pkgsrc using the SDF VPS pkgsrc. It also assumes that you have followed the OpenLDAP on NetBSD tutorial and have a working OpenLDAP server. It also assumes that you have a domain name and have set your VPS as your nameserver. If you do not have a domain name, you should register one. AFAIK, you can register a domain for free from dot.tk which will allow you to configure your own nameserver.
A DNS server can, like LDAP, be used for an almost endless number of things. It is also a hierachical database. Primarily though, it is for storing information about hosts such as their addresses, where the mail should be sent and who is responsible for them. A common analogy for DNS is