How do fears about immigration factor into the 2016 brexit vote?

The event of Brexit was when Britain decided to exit from the rest of the European countries. Considering the immigration policy of the Brexit, it decided that it will have the same immigration policy for the European countries like it has for the rest of the countries of the world.

It also decided to cut the number of people entering Britain because it wanted to give more employment opportunities to it's own citizens and reduce other races coming.