Electoral system - Wikipedia

An electoral system is the use of particular voting systems to place some group of people in charge of adminstration of a legal system under pre-existing legal codes, which typically require special measures, e.g. constitutional change, to modify. Study of comparative political and electoral systems, and ethics in public life, is called civics.

An electoral system allows for varying degrees of power for political party mechanisms, which may or may not be formally recognized, but usually organize the recruiting and coaching of candidates, and provide much of the platform they promise to implement legislatively. Electoral reform is often motivated by dissatisfaction with the role of parties and perceptions of fairness in how groups of people with different political views are treated.

The most widespread electoral systems are:

one-party state in which only members of a specific party can hold office, and only members of that party are empowered to vote on any measure (often indistinguishable from a dictatorship with no electoral system).
presidential state[?] in which the head of state is typically an elected executive, and has some degree of veto power of formal disapproval over lower legislatures.
parliamentary democracy[?] in which a single legislature exercises power, and selects a prime minister to perform executive functions. This is almost always the party leader of the party with the most seats. The head of state in such a system is typically not elected at the same time, or at all, e.g. in a constitutional monarchy where that head of state is a monarch or appointed representative.