Dictatorship is a system in which a single person rules the entire nation. Dictatorship is very similar to autocracy, since the reins of power remain in the hands of an individual. The power of this individual is unlimited and uncontrolled. You are not accountable to anyone and none of your actions are subject to legal review.
A dictator often becomes a tyrant because he knows that he does not need to justify any of his policies, he is supreme in his country and he does not need the consent of the people to do what he wants.
Dictatorships are often characterized by death or murder due to greed, hatred, pride, and power. Adolf Hitler of Germany is believed to have caused millions of Jewish deaths, and Idi Amin is responsible for the murders of hundreds of thousands of Indians.
Dictatorship could be the result of a single party ruling a country, with its boss as dictator or by a military dictatorship, where the head of the military assumes all powers.
Autocracy is a political system of government in which a single person controls the affairs, lives and decisions of all the people in his country. All decisions made by him are considered supreme and are not subject to any laws of the country.
Autocracy is a Greek word that translates to self-government. There is no rule of law as in the case of democracy, and there is no one whom this supreme ruler consults while making decisions.