If you want your domain to be reachable on the internet, you need to have it listed on a nameserver.
A nameserver is a web server that has DNS software installed. The server is usually managed by a webhost or registrar and is designed for managing the domain names. Every website has at least two nameservers to which it is pointed. Most of the registrars provide free nameserver for handling the domains. However, some do not – and that means that you have to set a nameserver on your own server or use an external service for it.
Nameserver is an effective point where you can protect your domain from spam traffic. There are external nameserver provider services (e.g. Cloudflare) where the traffic to your domain is constantly monitored and bad faith traffic is efficiently filtered.
Some of GoDaddy’s nameservers: