specifically the all-embracing all-pervading nature of totalitarian authority, connoted by the use of the term "total-" in the name.
quotations below are snagged from
Answers.com, with emphases added by your friend and humble narrator:
...from the Britannia Concise DictionaryForm of government that subordinates
all aspects of its citizens' lives to the authority of the state, with a single charismatic leader as the ultimate authority. The term was coined in the early 1920s by Benito Mussolini, but totalitarianism has existed throughout history throughout the world (e.g., Qin dynasty China).
It is distinguished from dictatorship and authoritarianism by its supplanting of all political institutions and all old legal and social traditions with new ones to meet the state's needs, which are usually highly focused.
...from the Columbia Encyclopediaa modern autocratic government in which the state involves itself in all facets of society, including the daily life of its citizens.
A totalitarian government seeks to control not only all economic and political matters but the attitudes, values, and beliefs of its population, erasing the distinction between state and society. The citizen's duty to the state becomes the primary concern of the community, and the goal of the state is the replacement of existing society with a perfect society.
* * *
Despite the many differences among totalitarian states, they have several characteristics in common, of which the two most important are:
the existence of an ideology that addresses all aspects of life and outlines means to attain the final goal, and a single mass party through which the people are mobilized to muster energy and support...
The party leadership maintains monopoly control over the governmental system, which includes the police, military, communications, and economic and education systems. Dissent is systematically suppressed and people terrorized by a secret police. Autocracies through the ages have attempted to exercise control over the lives of their subjects, by whatever means were available to them, including the use of secret police and military force.
However, only with modern technology have governments acquired the means to control society; therefore, totalitarianism is, historically, a recent phenomenon.
... from the Houghton Mifflin Political DictionaryDomination by a government of all political, social, and economic activities in a nation. Totalitarianism is a phenomenon of the twentieth century:
earlier forms of despotism and autocracy lacked the technical capacity to control every aspect of life....from WikipediaTotalitarianism is a term employed by some political scientists, especially those in the field of comparative politics, to describe
modern regimes in which the state regulates nearly every aspect of public and private behavior.The most influential scholars of totalitarianism, such as Karl Popper, Hannah Arendt, Carl Friedrich, Zbigniew Brzezinski, and Juan Linz have each described totalitarianism in a slightly different way. Common to all definitions is the attempt to mobilize entire populations in support of the official state ideology, and the
intolerance of activities which are not directed towards the goals of the state, entailing repression or state control of business, labour unions, churches or political parties. Totalitarian regimes maintain themselves in political power by means of secret police, propaganda disseminated through the state-controlled mass media, regulation and restriction of free discussion and criticism, the use of mass surveillance, and widespread use of terror tactics.