Left communism is the range of communist viewpoints held by the communist left, which criticizes the political ideas and practices espoused—particularly following the series of revolutions which brought the First World War to an end—by Bolsheviks and by social democrats.
Hybrid dictatorships are regimes that blend qualities of personalist, singleparty, and military dictatorships. When regimes share characteristics of all three forms of dictatorships, they are referred to as triple threats. The most common forms of hybrid dictatorships are personalist/single-party hybrids and personalist/military hybrids.
An oligarchic regime, also known more succinctly as an oligarchy, is any type of governing body that is answerable only to itself, and which is self perpetuating because it elects its own new members, as old members retire or die. The most familiar example is the politburo, in a country that is ruled by a communist dictatorship.
A republic (Latin: res publica) is a form of government in which the country is considered a "public matter", not the private concern or property of the rulers. The primary positions of power within a republic are not inherited. It is a form of government under which the head of state is not a monarch.
A wide variety of regime types exist. For example, the United Kingdom has a constitutional monarchy, in which Queen Elizabeth holds a limited amount of power. Theoretically, the queen is the English head of state, but over time the English monarchy has become largely ceremonial.
Absolutism, the political doctrine and practice of unlimited centralized authority and absolute sovereignty, as vested especially in a monarch or dictator. The essence of an absolutist system is that the ruling power is not subject to regularized challenge or check by any other agency, be it judicial, legislative, religious, economic, or electoral.
The advantages of an autocratic government are that decisions can be made and implemented quickly. However, individual rights are usually ignored and power is often maintained by force. Some autocracies are theocratic governments, in which the ruler claims to have been put in power by a deity.