Final answer:
An oligarchy is a form of government where a small ruling group holds power based on wealth, military might, or other forms of dominance, rather than through democratic means or hereditary succession as in a monarchy.
Step-by-step explanation:
A small ruling group holds power in a government structure known as an oligarchy. This is a situation where the control of a nation or organization is in the hands of a few individuals. Those who are part of this elite may not inherit their status through noble lines, as is common in a monarchy, but may gain it through other means such as wealth, military strength, or economic dominance.
Historically, oligarchies have contrasted with more democratic forms of government where power is more broadly distributed among the population. In an oligarchy, the ruling group exerts significant influence over the society's resources, policies, and laws. They may form based on various systems such as aristocracies, where power is derived from noble succession, or caste systems, which are highly stratified societies where social status is largely hereditary.
Furthermore, an oligarchic government does not function as a true democracy, since the chance for broader participation in decision-making is generally limited to the ruling elite. This can result in a concentration of power that shapes the politics and decision-making processes of a state or society.