Both are locations and not types of citizenship. 'British' is a descriptor for citizenship 'Great Britain' and 'United Kingdom' are not.
To be picky, there are technically 6 different types of British citizenship:
To be picky, there are technically 6 different types of British citizenship:
It also makes it a pain to find, I spent a good amount of time looking through different entries (UK, United Kingdom, British, England, Great Britain etc.).