domain
noun [ C ]
uk/dəʊˈmeɪn/ usa particular interest, activity, or type of knowledge
a business activity that is controlled by a particular industry, group of people, etc.:
Despite many advertising agencies having moved into their domain, specialised direct marketing agencies remain very competitive.
Currency trading is usually the domain of big banks.
Boardroom decisions are the exclusive domain of company directors.
the political/scientific domain
See also
the private domain
the public domain
INTERNET
a group of computers or websites that are organized by purpose, for example, to provide education or sell products:
The organization met to discuss adding new 'top-level' domains, the global designations such as .com and .gov.