What is the meaning of .org, .in , .net ,co.in , com , .uk ,?

Hello, we always use the internet and we notice that ech siteweb end with a specific domaine as . com .fr and many others, so here we will be showing you there meaning:

org-organisation(non-profit)

.in-india
.net-network
.co.in-company in India
.uk-united kingdom
Apart from these there are other common domain names like:-
.com-commercial organisation
.pk-pakistan
.au-australia
.edu-educational institutions
.ac-academic institutions
.res-research institutes
.ernet-educational and research institutes
.gov-government site
.mil-military
.nic.in-national informatics centre(basically reserved for National 
Informatics Centre but in practice most Indian government 
agencies have domains ending in .nic.in.)
.um- united states minor outlying islands 

and the list is doesnt end..........