A Dictator is someone who rules a country either without being elected, or is initially elected but decides to extend their term without risking an election at the end of their elected term of office. That type of government is called dictatorship.
If dictators then start handing power over to their biological descendants it becomes a Hereditary Absolute Monarchy like Saudi Arabia or North Korea. Dictator generally has negative connections attached to it, mostly because no one really wants to be ruled by the same person forever, especially if that is a person they didn't choose to be ruled by in the first place. Dictators almost always are corrupted by power and become tyrants.
Dictators can be of any ideology that tolerates an undemocratic form of Government. Fascism and Communism are ideologies that in practice almost always seem to wind up as dictatorships (though North Korea and possibly Cuba are evolving into monarchies). Conservatism can also be conducive to Dictatorship, both because Conservatives values "strong and authoritative" Government and because WASPish Conservatives sometimes see Democracy as the rule of the rabble.