The video tutorial explains the DNS service from the perspective of a client and server. It highlights the simplicity of DNS requests and responses, followed by a discussion on DNS facts, such as the number of active domains, domain expiration, and the complexity of managing DNS records. The tutorial concludes with the challenges of storing DNS data on a single server and introduces the hierarchical structure of the worldwide DNS registry.

What is the primary function of a DNS server?

How many active domains are there approximately in the world?

What happens to DNS records over time?

What is the role of a DNS registrar?

Why is it difficult to keep all DNS data on a single server?