Queen is the title of a woman who rules a kingdom in her own right, or who is the wife of a king. If she rules in her own right, she is called a queen regnant. She has the same powers that a king would have, depending on the constitution of the country she rules.
If the queen is the wife of the king, she is called a queen consort. The mother of the ruling monarch is the queen mother, and the widow of a king is a queen dowager. Each of the queens has her own household. But none exercises any official power in the government.
Kings or queens of the United Kingdom and other constitutional monarchies have few powers of government. But they can refuse the advice of the prime minister, and they can influence public opinion.
