The main difference between Aristocracy and Plutocracy is that the Aristocracy is a form of government in which power is in the hands of a small, privileged, ruling class and Plutocracy is a society or system ruled and dominated by the small minority of the top wealthiest citizens
Aristocracy (Greek ἀριστοκρατία aristokratía, from ἄριστος aristos ‘excellent’, and κράτος, kratos ‘rule’) is a form of government that places strength in the hands of a small, privileged ruling class. The term derives from the Greek aristokratia, meaning ‘rule of the best-born’.The term is synonymous with hereditary government, and hereditary succession is its primary philosophy, after which the hereditary monarch appoints officers as they see fit. At the time of the word’s origins in ancient Greece, the Greeks conceived it as rule by the best qualified citizens—and often contrasted it favourably with monarchy, rule by an individual. In later times, aristocracy was usually seen as rule by a privileged group, the aristocratic class, and has since been contrasted with democracy. The idea of hybrid forms which have aspects of both aristocracy and democracy are in use in the parliament form.
Plutocracy (Greek: πλοῦτος, ploutos, ‘wealth’ + κράτος, kratos, ‘rule’) or plutarchy, is a form of society defined as being ruled or controlled by a function of wealth or higher income. The first known use of the term was in 1631. Unlike systems such as democracy, capitalism, socialism or anarchism, plutocracy is not rooted in an established political philosophy. The concept of plutocracy may be advocated by the wealthy classes of a society in an indirect or surreptitious fashion, though the term itself is almost always used in a pejorative sense.
The nobility, or the hereditary ruling class.
Government by such a class, or a state with such a government
A class of people considered (not normally universally) superior to others
Government by the wealthy.
A controlling class of the wealthy.
the highest class in certain societies, typically comprising people of noble birth holding hereditary titles and offices
“members of the aristocracy”
a form of government in which power is held by the nobility.
a state in which governing power is held by the nobility.
a group regarded as privileged or superior in a particular sphere
“Britain’s pop aristocracy”
“a new aristocracy of talented young people”