There's a recent discussion here https://community.spiceworks.com/topic/1871816-good-dns-host... about DNS providers and why using for instance CloudFlare DNS rather than your registrar's DNS servers is a good idea.

TLDR: Hover is a domain reseller and DNS provider who a few days ago suffered a DDoS attack which disrupted everyone who was using their DNS servers. Hopefully if you had your domain registered with Hover, but used CloudFlare DNS you'd not have experienced any disruption.