An Electoral system is the set of rules that determines how elections and referendums are conducted and how their results are determined. Political electoral systems are organized by governments, while non-political elections may take place in business, non-profit organisations and informal organisations.
Electoral systems consist of sets of rules that govern all aspects of the voting process: when elections occur, who is allowed to vote, who can stand as a candidate, how ballots are marked and cast, how the ballots are counted (electoral method), limits on campaign spending, and other factors that can affect the outcome. Political electoral systems are defined by constitutions and electoral laws, are typically conducted by election commissions, and can use multiple types of elections for different offices.
Some electoral systems elect a single winner to a unique position, such as prime minister, president or governor, while others elect multiple winners, such as members of parliament or boards of directors. There are a large number of variations in electoral systems, but the most common systems are first-past-the-post, the two-round (runoff) system, proportional representation and ranked or preferential voting. Some electoral systems, such as mixed systems, attempt to combine the benefits of non-proportional and proportional systems.