A top-level domain, or TLD, are the letters that follow the final dot of the domain names.
There are several kinds of TLDs:
- Infrastructure: One TLD, the .arpa
- Countries: Usually they are codes with two letters according to ISO 3166.
- Sponsored: They are promoted by collectives, organizations, the US government or territories with its own language and culture.
- Generic: They are .com, .net, .org and .info.
- Generic restricted: .edu, .gov, .mil