A domain is the unique and exclusive name given to a website on the Internet for anyone to visit.
When we talk about types, we really mean the 2 main types that exist in top level domains or TLDs, what I previously called a domain "extension" (.com, net, .es, and .org).
CcTLDs (Country Code Top Level Domains), also called geographic or territorial locations, are reserved for different countries or territories in the world and use the two letter country code as an extension of the domain.
GTLDs (generic top-level domain) were originally assigned according to the purpose for which they were reserved (for example, .com was commercial, .org was for organizations, etc.), but most can now be used for you want, without restrictions.
These domains use at least three letters in their extension and would include .com, .org, .net, .gov, .edu, .info, .biz, etc.
Within generic domains, you can also find so-called top-level sponsored domains or top-level sponsored domains (sTLDs). They are administered by independent agencies or foundations that restrict their use, such as .gov only for the US government. USA Or .edu for educational purposes only.
Domain name registrations are overseen by an organization called ICANN (Internet Corporation for Assigned Names and Numbers). ICANN specifies which domain extensions are available and maintains a centralized database of where web domains point to.