In a republic, the people elect representatives to make and enforce laws. A monarchy consists of rule by a king or queen. There are no large monarchies today. The United Kingdom, which has a queen, is really a republic because the queen has virtually no political power. An aristocracy is rule by the aristocrats.
Aristocrats are typically wealthy, educated people.
Many monarchies have really been ruled by aristocrats. Dictatorship A dictatorship consists of rule by one person or a group of people. The dictator may be one person, such as Castro in Cuba or Hitler in Germany, or a group of people, such as the Communist Party in China. Communist dictatorships have been especially prone to use this term.