There are many types of web hosting and one of the least known to the end user is called DNS hosting. If you have come across this type and want to be sure if you need this for making your website live on the internet, then the answer is most probably NO.
DNS hosting is basically a hosting service that hosts Domain Name Servers. A domain name server is a kind of server that maps IP addresses to domain names. There are two main benefits of domain name system.
First of all it maps the difficult to remember IP address on which a website is hosted to a human understandable domain name for that website. This means that websites many change any server which essentially means changing IP address, and still users will be able to find them by going to the same domain name courtesy DNS hosting because every website has an authoritative domain name server which can be updated quickly.
Most of the domain registrars offer basic level of DNS hosting so you do not need to buy any special DNS hosting because domain registrars like GoDaddy already offer basic DNS where you can edit A, MX, CNAME, TXT and NS records of your domain. 99 percent of the websites are concerned with these domain names records.
If you are with a second level or third level domain, then you will need to look for DNS hosting. There are some very good free DNS hosting service providers as well as premium paid services too. For example, if you are using self managed VPS hosting, it will be a good idea to have a DNS hosting outside the VPS to increase availability.
Another benefit of professional DNS hosting is that they have DNS servers across different geographical regions which means faster DNS query response and lower latency increasing the overall website loading speed.
There are some very good DNS hosting services around. Free DNS is the most popular among free options. Most of the good hosting companies also offer cPanel DNS hosting. My personal favorite is DNS hosting from RamNode which is free if you have a VPS with them. Other popular commercial names include DynDNS, CloudFlare and EasyDNS.