when you are registering a new domain you can have two choice, either register a domain which is top level ( .com, .net, .org etc ) or register country specific domain (.co.uk, .us. .ie etc ).
It doesn't make much difference with normal website user but make huge difference in promotion in different countries.
country specific domain performs well in SERP with specific geographic location.
Top level domain performs well in search engine with global search in different location across the world with no filtering criteria.
if you have multilingual website, having top level domain with main language and other languages as sub domain will get you higher ranking in SERP.
you should prefer country specific domain if your targeted audience is limited to specific one country only. If you want to expand your business in other countries as well in future, you must prefer top level domain.
so before making any decision on domain selection, you should prefer above criteria.