Naturalisation is a process of getting citizenship of a country through residence. Just like a lot of other countries in the world, UK allows immigration to acquire British Citizenship. UK law allows dual citizenship but the other country, normally country of your Birth, may not allow to have nationality of an other country. Therefore it is very important that you check this before making an application for Naturalisation in UK. India is an example of a country which does not allow dual citizenship.
british citizenship requirements
FAQs about Naturalisation. Documents required for British naturalisation application. Effect of convictions on application for British Citizenship.