Question: what are the types of domain name system?
Answer: TLD - Top Level Domains. These are at the highest level in the DNS structure of the Internet. ... 
ccTLD - country code Top Level Domains. ... 
gTLD - generic Top Level Domain. ... 
IDN ccTLD - internationalised country code top-level domains. ... 
Second level. ... 
Third level. ... 
Subdomain.