CANZUK is a name taken from Canada, Australia, New Zealand and the United Kingdom.
CANZUK is a organisation advocating freedom of movement, free trade and foreign policy coordination.
Free trade will positively influence to each others economy.
And freedom of movement allows Citizen to travel freely, without thinking of visa, between the countries.
This link details more on what CANZUK is trying to achieve.
Know what they do and keep up to date with their activity by going to their news page!