Final answer:
In a dictatorship, one person makes all the decisions, holding complete power usually after rising to it through economic or military means. An oligarchy involves power held by a small, elite group due to aspects such as military strength or economic power, as opposed to monarchies where power is hereditary or divinely appointed.
Step-by-step explanation:
In a dictatorship, one person makes all of the decisions regarding the practice. A dictatorship is a form of government in which a single person or a very small group exercises complete and absolute authority over a government or populace. This rise to power is usually achieved through economic or military might. Unlike a monarchy, which is a form of government run by a single person who rules until they die or abdicate and often claims the rights to the title by virtue of hereditary succession or divine appointment, a dictatorship does not necessarily have a hereditary basis. A monarchy can also be part of a constitutional monarchy, where the monarch's powers are limited by a constitution and are largely ceremonial, unlike in absolute monarchies where the monarch has unrestricted power.
Addressing a related form of government, an oligarchy is when power is held not by one person, but by a small elite group. Members of an oligarchy might ascend to power not through hereditary means but rather due to military might, economic power, or similar circumstances. This differs from a monarchy, where the role of the leader is usually based on noble ancestry or succession.