Most simply, authoritarianism denotes the absence of free elections and the presence of unconstrained power. In this form of non-democratic government, the power and authority wielded by the leader(s) is not contingent upon popular support from the citizenry. Authoritarian leadership may be single or group headed. When a single person heads the government, it is known as an autocracy. When an elite group of individuals head the government, it is known as an oligarchy; such an elite ruling group is also sometimes known as a junta. Furthermore, individual leaders may vary substantially in how they govern. Those who are somewhat concerned with the betterment of the public good are known as benevolent autocrats. Those who are concerned solely with advancing their own interests are known as dictators. Those who exhibit great enthusiasm for violence and bloodshed are known as tyrants. No matter which style of leadership is expressed in an authoritarian state, the interests of the rulers will always be paramount to the welfare of the citizenry because the rulers are not accountable to the people.

Although some authoritarian leaders may come to power through elections, they usually gain it through the use of force or violence. An authoritarian regime tends to overthrow the existing government in a coup d'état. Thus, leaders initially tend to assume a militant status, and then later convert to a civilian status for the sake of appearances. For example, Nassar of Egypt was a military commander before becoming president. This is a tricky game of grasping and maintaining political power. After all, as has been seen in Asia, Africa, and Latin America, these regimes have often seized power only to be overthrown by equally forceful autocrats or juntas. In a system where power can be achieved through violence, there is always the risk that a stronger regime will come along and take it away. Consequently, authoritarian regimes, out of necessity, must tightly control the army and the police which are the primary means by which political opponents can be harassed, exiled, or even executed.

Although there is no elaborate or guiding ideology of authoritarianism, there are defining commonalties. Authoritarian regimes do not attempt to control every aspect of society and their main goal is simply the preservation of their own political power. Nonetheless, authoritarian states all tend to possess the following features, although they may vary greatly in the: 1) degree of oppression they impose upon the citizens. 2) amount of force, repression, and violence they use to achieve their goals. 3) degree of enforced public conformity through such means as suppression of intellectual freedom. 4) degree of public support that they enjoy.

Authoritarian regimes express principles which are fundamentally at odds with democracy such as rule by a select few, suppression of the opposition, and so on. However, this does not necessarily mean that they are seen as lacking legitimacy in the countries in which they govern. They may be legitimized and also gain popularity from a variety of means. For example, they may secure both legitimacy and popularity by bringing much needed stability and/or economic growth to the state. The presence of a charismatic leader can also be an important source of legitimacy and popularity for these regimes, as was the case with Qaddafi of Libya.

Authoritarianism is the oldest and most common form of government. For example, in Europe, from the Middle Ages to the French Revolution of 1789 absolute monarchy, a form of authoritarianism, was the only form of government in existence. Furthermore, the principle alternative to the monarchy in the Greek city-states was oligarchy, another form of authoritarianism. This form of government has likely been the norm throughout history because it is so simple. After all, it is the easiest to institute and it can still provide a straightforward and efficient governmental response to the need for order and stability, as well as a solution to severe social and economic problems. The deep roots of authoritarianism can be seen in the writings of Niccolò Machiavelli, the famous Italian political thinker, who wrote in 1532 about gaining and maintaining political power the authoritarian way. Despite the enduring nature of authoritarianism, the 1980s and 1990s have signified a shift away from this mode of governance as global enthusiasm for democracy has increased. However, the fact remains that the vast majority of states, especially those that are still developing, subscribe to this non-democratic form of government known as authoritarianism.