The major types of electoral systems include plurality, majoritarian, proportional representation, and mixed systems. Plurality systems, such as the first-past-the-post, elect candidates who have the most votes, regardless of achieving a majority. Majoritarian systems require a candidate to secure more than 50% of the vote, often leading to runoff elections. Proportional representation allocates seats based on the percentage of votes each party receives, promoting minority representation. Mixed systems combine elements of both plurality and proportional representation, allowing for both local representation and proportionality in legislative bodies.