Posts on British citizenship may be found here.

British citizenship is the principal class of British nationality. It describes the legal attachment or bond of persons who may be said to belong to the United Kingdom  (and –  in important respects – to all the British overseas territories save one).

It is a creation of statute and the core provision for it is found in Part I of the British Nationality Act 1981.

By virtue of sections 1 and 2 of the Immigration Act 1971 a British citizen has the right of abode in the UK, and so he or she is entitled to live in, come and go into and from, the UK. In other words a British citizen may live and work in the UK free of immigration controls.

A British citizen is a UK national for the purposes of EU law and a British citizen holds the additional status of EU citizen.  Save for a small number associated with the British Crown Dependencies (Channel Islands and the Isle of Man), British citizens have rights of free movement within the European Union.

British citizenship has modes of automatic acquisition, for example  through birth in the UK to a parent holding a relevant status, or by descent from a British citizen otherwise than by descent. It also has modes of acquisition that require an application to be made and thereafter a grant of citizenship by way or naturalisation or registration.

British citizenship also has modes of loss. For example it may be renounced,  or it may lost through deprivation of citizenship on grounds of fraud or conduct.

Posts on British citizenship may be found here.