Hi

Also known as domain suffixes or TLDs (Top Level Domains), domain extension is the part that comes after the dot (.) in a domain name. They are introduced by ICANN (Internet Corporation for Assigned Names and Numbers). The most popular domain extension is .com but there are many other popular domain extensions such as .org etc. Domain extensions can be either generic (.com, .org, .blog), generic-restricted (.pro), country code (.cn, .us) or sponsored (with restrictions to the type of websites that can use these extensions; .edu, .gov).

Hope this helped.