Is the Queen of Great Britain the Queen of other countries?

She is a real queen only in Great Britain itself, although it is worth saying that nominally she also has such a high title in other countries. At the moment, this applies to the countries of the so-called British Commonwealth. It refers to countries that were previously part of the British Empire. Today, she is formally the monarch for countries such as Canada or Australia. In fact, these countries have their own completely independent system of government.