The word Government has two meanings in British Politics:-
Government is those institutions that are publicly run. This is compared to other institutions in society such as the voluntary sector, firms or trade unions.
Local government and the devolved governments in Scotland, Wales and Northern Ireland are part of the public sector, the remainder make up Central Government.
The Government is the set of politicians who are currently in charge of running Central Government institutions.
They are able to do this on the basis of their control of the House of Commons.